source: trunk/exports/cif_pd.dic @ 3024

Last change on this file since 3024 was 1067, checked in by toby, 8 years ago

CIF updates

File size: 115.2 KB
Line 
1##############################################################################
2#                                                                            #
3#                        Powder CIF Dictionary                               #
4#                        ---------------------                               #
5#                                                                            #
6#  CIF data definitions specifically for powder diffraction applications.    #
7#  These are in addition to those defined in the Core CIF Dictionary 1996.   #
8#                                                                            #
9#  The DDL commands used in this dictionary are defined in "ddl_core.dic".   #
10#                                                                            #
11##############################################################################
12
13data_on_this_dictionary
14
15    _dictionary_name            cif_pd.dic
16    _dictionary_version         1.0.1
17    _dictionary_update          2005-06-14
18    _dictionary_history
19;
20  1991-08-28  Initial definitions                                  B.H. Toby
21  1991-09-15  More definitions added                               B.H. Toby
22  1991-09-21  Still More definitions                               B.H. Toby
23  1991-09-24  Some updates from down under  |:-)                   S.R. Hall
24  1991-10-07  Unable to leave well enough alone...                 B.H. Toby
25  1991-10-10  Some additional fine tuning   (-:|                   S.R. Hall
26  1991-10-14  Minor touchups                                       B.H. Toby
27  1991-12-08  Back to Work...                                      B.H. Toby
28  1992-01-07  Add _pd_refln_ to allow for mixtures                 B.H. Toby
29  1992-02-07  Some redefinitions                                   S.R. Hall
30  1992-02-25  Defining standards is a fiddly business              S.R. Hall
31  1992-03-18  And still more...                                    B.H. Toby
32  1992-05-22  Minor cleanup                                        B.H. Toby
33  1992-05-23  Quasar says that all is OK now...                    S.R. Hall
34  1992-05-30  Changes from comments @ APD-II                       B.H. Toby
35  1992-08-18  Add calculated pattern definitions                   B.H. Toby
36  1992-08-28  Change 'powder' to 'pw'                              B.H. Toby
37  1992-08-31  Major overhaul of some definitions                   B.H. Toby
38  1992-09-01  Small adjustments                                    S.R. Hall
39  1992-10-01  Change 'pw' to 'pd'                                  B.H. Toby
40  1993-04-16  Change usage for multiple detectors                  B.H. Toby
41  1993-04-19  Change *_raw_ to *_meas_; *_sample_ to *_samp_
42              Install new DDL commands; new *_phase_ group         S.R. Hall
43  1993-05-22  Fix _pd_calib_ defs; Minor editing                   B.H. Toby
44  1993-05-31  Still more minor editing                             B.H. Toby
45  1993-06-02  Application of new DDL commands                      S.R. Hall
46  1993-08-13  Last stop before Beijing, more descriptive entries &
47              more descriptive text added; support for film data.  B.H. Toby
48  1993-10-27  My two cents worth                                   I.D. Brown
49  1994-01-23  Change two to 2.5; sample to specimen.               B.H. Toby
50  1994-03-13  Change date/time usage
51              Be more careful about pd_proc usage: separate data
52              & processing conditions                              B.H. Toby
53  1994-04-11  Start work on categories: move all diffractogram
54              items (that might ever be in a single loop) into
55              pd_data.                                             B.H. Toby
56  1994-05-11  Start revisions based on I.D. Brown's comments       B.H. Toby
57  1994-06-25  Complete revisions prior to ACA                      B.H. Toby
58  1994-10-27  Working draft                                        B.H. Toby
59  1995-10-23  Implemented _units and _units_detail                 B. McMahon
60  1995-10-24  Transferred _pd_instr_radiation_probe to the core
61              as _diffrn_radiation_probe                           B. McMahon
62  1997-01-30  Final cleanup: removed _nm units; add units to
63              definitions; add _pd_block_diffractogram_id;
64              change _pd_meas_distance_value to _pd_meas_position;
65              remove _pd_proc_wavelength_nm, _pd_proc_d_spacing_nm;
66              _pd_proc_recip_len_Q_nm, and _pd_peak_d_spacing_nm
67                                                                   B.H. Toby
68  1997-01-31  Changed dictionary_definition to category_overview;
69              removed data_include_dependent_dictionaries and global_
70              blocks; some typos fixed                             B. McMahon
71  1997-02-12  Some typos fixed                                     B. McMahon
72  1997-02-18  References to e.s.d. changed to s.u. etc.
73              Notation for Bragg and expected R factors changed to
74              R~B~ and R~exp~
75                                                                   B. McMahon
76  1997-03-10  Category of _pd_refln_ things changed to 'refln'; category of`
77              _pd_proc_number_of_points changed to 'pd_proc_info'; some
78              rewording of descriptions involving s.u.s according to BT;
79              changed 'samp' to 'spec' in many datanames relating distances
80              to specimen; changed style of these and similar to *_src/spec
81              etc; _pd_calc_method no longer has '_list yes'; _list_uniqueness
82              deleted from _pd_refln_peak_id; use of '.' instead of '?'
83              recommended in a couple of places; addition of example to
84              _pd_calib_conversion_eqn; '_pd_proc_intensity_calc_bkg' and
85              '_fix_bkg' changed to '_pd_proc_intensity_bkg_calc' and '_fix'
86                                                                   B. McMahon
87  1997-03-12  Category of _pd_calib_ things changed to 'pd_calib';
88              _pd_calib_conversion_eqn and *_special_details renamed as
89              _pd_calibration_* and assigned to category 'pd_calibration'
90              Alphabetised entries within category.
91                                                                   B. McMahon
92  1997-03-17  Copyediting changes to punctuation and spelling.     B. McMahon
93  1997-10-29  Changed _pd_calib_std_external_id to
94              _pd_calib_std_external_block_id. Moved _pd_proc_2theta_range_ to
95              category pd_proc_info (because not looped with other pd_data
96              items).
97                                                                   B. McMahon
98  1997-10-29  Release version 1.0                                  B. McMahon
99  2005-01-07  NJA: minor corrections to hyphenation, spelling and punctuation
100                   pd_data_[pd]: Example 3, second loop _pd_calc_2theta_scan
101                   changed to _pd_proc_2theta_corrected
102                   _pd_instr_cons_illum_len: definition rephrased
103                   _pd_phase_[pd]: first sentence of definition rephrased
104                   _pd_proc_ls_background_function: second paragraph of
105                   definition rephrased
106;
107
108#......................... Block/Data set names
109
110data_pd_block_[pd]
111    _name                       '_pd_block_[pd]'
112    _category                     category_overview
113    _type                         null
114    _definition
115;              _pd_block_id is used to assign a unique ID code to a data block.
116               This code is then used for references between different blocks
117               (see _pd_block_diffractogram_id, _pd_calib_std_external_block_id
118               and _pd_phase_block_id).
119
120               Note that a data block may contain only a single diffraction
121               data set or information about a single crystalline phase.
122               However, a single diffraction measurement may yield structural
123               information on more than one phase, or a single structure
124               determination may use more than one data set. Alternatively,
125               results from a single data set, such as calibration parameters
126               from measurements of a standard, may be used for many subsequent
127               analyses. Through use of the ID code, a reference made between
128               data sets may be preserved when the file is exported from the
129               laboratory from which the CIF originated.
130
131               The ID code assigned to each data block should be unique with
132               respect to an ID code assigned for any other data block in the
133               world. The naming scheme chosen for the block-ID format is
134               designed to ensure uniqueness.
135
136               It is the responsibility of a data archive site or local
137               laboratory to create a catalogue of block ID's if that site
138               wishes to resolve these references.
139;
140
141data_pd_block_diffractogram_id
142    _name                      '_pd_block_diffractogram_id'
143    _category                    pd_proc
144    _type                        char
145    _list                        yes
146    _definition
147;              A block ID code (see _pd_block_id) that identifies
148               diffraction data contained in a data block other
149               than the current block. This will occur most frequently
150               when more than one set of diffraction data
151               is used for a structure determination. The data
152               block containing the diffraction data will contain
153               a _pd_block_id code matching the code in
154               _pd_block_diffractogram_id.
155;
156
157data_pd_block_id
158    _name                      '_pd_block_id'
159    _category                    pd_block
160    _type                        char
161    _list                        both
162    loop_ _example
163                         1991-15-09T16:54|Si-std|B.Toby|D500#1234-987
164                         1991-15-09T16:54|SEPD7234|B.Toby|SEPD.IPNS.ANL.GOV
165    _definition
166;              Used to assign a unique character string to a block.
167               Note that this code is not intended to be parsed; the
168               concatenation of several strings is used in order to
169               generate a string that can reasonably be expected to
170               be unique.
171
172               This code is assigned by the originator of the data set and
173               is used for references between different CIF blocks.
174               The ID will normally be created when the block is first
175               created. It is possible to loop more than one ID for a
176               block: if changes or additions are made to the
177               block later, a new ID may be assigned, but the original name
178               should be retained.
179
180               The format for the ID code is:
181                 <date-time>|<block_name>|<creator_name>|<instr_name>
182
183                <date-time>    is the date and time the CIF was created
184                               or modified.
185
186                <block_name>   is an arbitrary name assigned by the
187                               originator of the data set. It will
188                               usually match the name of the phase
189                               and possibly the name of the current CIF
190                               data block (i.e. the string xxxx in a
191                               data_xxxx identifier). It may be a sample name.
192
193                <creator_name> is the name of the person who measured the
194                               diffractogram, or prepared or modified the CIF.
195
196                <instr_name>  is a unique name (as far as possible) for
197                               the data-collection instrument, preferably
198                               containing the instrument serial number for
199                               commercial instruments. It is also possible to
200                               use the Internet name or address for the
201                               instrument computer as a unique name.
202
203               As blocks are created in a CIF, the original sample identifier
204               (i.e. <block_name>) should be retained, but the <creator_name>
205               may be changed and the <date-time> will always change.
206               The <date-time> will usually match either the
207               _pd_meas_datetime_initiated or the _pd_proc_info_datetime
208               entry.
209
210               Within each section of the code, the following characters
211               may be used:
212                             A-Z a-z 0-9 # & * . : , - _ + / ( ) \ [ ]
213
214               The sections are separated with vertical rules '|' which are
215               not allowed within the sections. Blank spaces may also
216               not be used.  Capitalization may be used within the ID code
217               but should not be considered significant - searches for
218               data-set ID names should be case-insensitive.
219
220               Date-time entries are in the standard CIF format
221               'yyyy-mm-ddThh:mm:ss+zz' Use of seconds and a time zone
222               is optional, but use of hours and minutes is strongly
223               encouraged as this will help ensure that the ID code is unique.
224
225               An archive site that wishes to make CIFs available via
226               the web may substitute the URL for the file containing the
227               appropriate block for the final two sections of the ID
228               (<creator_name> and <instr_name>). Note that this should
229               not be done unless the archive site is prepared to keep the
230               file available online indefinitely.
231;
232
233#......................... Measured Diffractogram Information
234
235data_pd_meas_[pd]
236    _name                     '_pd_meas_[pd]'
237    _category                   category_overview
238    _type                       null
239    loop_
240        _example
241        _example_detail
242#----------------------------------------------------------------------------
243;
244    _pd_meas_info_author_name        'Cranswick, Lachlan'
245    _pd_meas_info_author_email       lachlan@dmp.csiro.au
246    _pd_meas_info_author_address     ?
247    _pd_meas_datetime_initiated      1992-03-23T17:20
248
249    _pd_meas_scan_method             step
250    _pd_meas_2theta_range_min        6.0
251    _pd_meas_2theta_range_max        164.0
252    _pd_meas_2theta_range_inc        0.025
253    _pd_meas_step_count_time         2.0
254;
255;
256    Example 1.
257;
258#----------------------------------------------------------------------------
259    _definition
260;              This section contains the measured diffractogram and information
261               about the conditions used for the measurement of the diffraction
262               data set, prior to processing and application of correction
263               terms. While additional information may be added to the CIF
264               as data are processed and transported between laboratories
265               (possibly with the addition of a new _pd_block_id entry), the
266               information in this section of the CIF will rarely be changed
267               once data collection is complete.
268
269               Where possible, measurements in this section should have no
270               post-collection processing applied (normalizations, corrections,
271               smoothing, zero-offset corrections etc.). Such corrected
272               measurements should be recorded in the _pd_proc_ section.
273
274               Data sets that are measured as counts, where a standard
275               uncertainty can be considered equivalent to the standard
276               deviation and where the standard deviation can be estimated
277               as the square root of the number of counts recorded, should
278               use the _pd_meas_counts_ fields. All other intensity values
279               should be recorded using _pd_meas_intensity_.
280;
281
282data_pd_meas_2theta_fixed
283    _name                      '_pd_meas_2theta_fixed'
284    _category                    pd_meas_method
285    _type                        numb
286    _type_conditions             esd
287    _enumeration_range           -180.0:360.0
288    _definition
289;              The 2\q diffraction angle in degrees for measurements
290               in a white-beam fixed-angle experiment. For measurements
291               where 2\q is scanned, see _pd_meas_2theta_scan or
292               _pd_meas_2theta_range_.
293;
294
295data_pd_meas_2theta_range_
296    loop_ _name                '_pd_meas_2theta_range_min'
297                               '_pd_meas_2theta_range_max'
298                               '_pd_meas_2theta_range_inc'
299    _category                    pd_meas_method
300    _type                        numb
301    _enumeration_range           -180.0:360.0
302    _definition
303;              The range of 2\q diffraction angles in degrees for the
304               measurement of intensities. These may be used in place of the
305               _pd_meas_2theta_scan values for data sets measured with a
306               constant step size.
307;
308
309data_pd_meas_2theta_scan
310    _name                      '_pd_meas_2theta_scan'
311    _category                    pd_data
312    _type                        numb
313    _type_conditions             esd
314    _list                        yes
315    _enumeration_range           -180.0:360.0
316    _definition
317;              2\q diffraction angle (in degrees) for intensity
318               points measured in a scanning method. The scan method used
319               (e.g. continuous or step scan) should be specified in
320               the item _pd_meas_scan_method. For fixed 2\q (white-beam)
321               experiments, use _pd_meas_2theta_fixed. In the case of
322               continuous-scan data sets, the 2\q value should be the
323               value at the midpoint of the counting period. Associated
324               with each _pd_meas_2theta_scan value will be
325               _pd_meas_counts_ items. The 2\q values should
326               not be corrected for nonlinearity,
327               zero offset etc. Corrected values may be specified
328               using _pd_proc_2theta_corrected.
329
330               Note that for data sets collected with constant step size,
331               _pd_meas_2theta_range_ (*_min, *_max and *_inc) may be
332               used instead of _pd_meas_2theta_scan.
333;
334
335data_pd_meas_angle_
336    loop_ _name                '_pd_meas_angle_chi'
337                               '_pd_meas_angle_omega'
338                               '_pd_meas_angle_phi'
339                               '_pd_meas_angle_2theta'
340    _category                    pd_data
341    _type                        numb
342    _list                        both
343    _enumeration_range           -180.0:360.0
344    _definition
345;              The diffractometer angles in degrees for an instrument with a
346               Euler circle. The definitions for these angles follow the
347               convention of International Tables for X-ray Crystallography
348               (1974), Vol. IV, p. 276.
349;
350
351data_pd_meas_counts_
352    loop_ _name                '_pd_meas_counts_total'
353                               '_pd_meas_counts_background'
354                               '_pd_meas_counts_container'
355                               '_pd_meas_counts_monitor'
356    _category                    pd_data
357    _type                        numb
358    _list                        yes
359    _enumeration_range           0:
360    _definition
361;              Counts measured at the measurement point as a function of
362               angle, time, channel or some other variable (see
363               _pd_meas_2theta_ etc.).
364
365               The defined fields are:
366                 _pd_meas_counts_total, scattering from the specimen
367                   (with background, specimen mounting or container
368                   scattering included);
369                 _pd_meas_counts_background, scattering measured
370                   without a specimen, specimen mounting etc., often
371                   referred to as the instrument background;
372                 _pd_meas_counts_container, the specimen container or
373                   mounting without a specimen, includes background;
374                 _pd_meas_counts_monitor, counts measured by an
375                   incident-beam monitor to calibrate the flux on the
376                   specimen.
377
378               Corrections for background, detector dead time etc.
379               should not have been made to these values. Instead use
380               _pd_proc_intensity_ for corrected diffractograms.
381
382               Note that counts-per-second values should be converted to
383               total counts. If the counting time varies for different
384               points, it may be included in the loop using
385               _pd_meas_step_count_time.
386
387               Standard uncertainties should not be quoted for these values.
388               If the standard uncertainties differ from the square root of
389               the number of counts, _pd_meas_intensity_ should be used.
390;
391
392data_pd_meas_datetime_initiated
393    _name                      '_pd_meas_datetime_initiated'
394    _category                    pd_meas_method
395    _type                        char
396    _example                     1990-07-13T14:40
397    _definition
398;              The date and time of the data-set measurement. Entries follow
399               the standard CIF format 'yyyy-mm-ddThh:mm:ss+zz'. Use
400               of seconds and a time zone is optional, but use of hours
401               and minutes is strongly encouraged. Where possible, give the
402               time when the measurement was started rather than when
403               it was completed.
404;
405
406data_pd_meas_detector_id
407    _name                      '_pd_meas_detector_id'
408    _category                    pd_data
409    _type                        char
410    _list                        yes
411    _list_link_parent          '_pd_calib_detector_id'
412    _definition
413;              A code or number which identifies the measuring detector or
414               channel number in a position-sensitive, energy-dispersive
415               or other multiple-detector instrument.
416
417               Calibration information, such as angle offsets or
418               a calibration function to convert channel numbers
419               to Q, energy, wavelength, angle etc. should
420               be described with _pd_calib_ values. If
421               _pd_calibration_conversion_eqn is used, the detector ID's
422               should be the number to be used in the equation.
423;
424
425data_pd_meas_info_author_address
426    _name                      '_pd_meas_info_author_address'
427    _category                    pd_meas_info
428    _type                        char
429    _list                        both
430    _list_reference            '_pd_meas_info_author_name'
431    _definition
432;              The address of the person who measured the data set. If there
433               is more than one person, this will be looped with
434               _pd_meas_info_author_name.
435;
436
437data_pd_meas_info_author_email
438    _name                      '_pd_meas_info_author_email'
439    _category                    pd_meas_info
440    _type                        char
441    _list                        both
442    _list_reference            '_pd_meas_info_author_name'
443    _definition
444;              The e-mail address of the person who measured the data set. If
445               there is more than one person, this will be looped with
446               _pd_meas_info_author_name.
447;
448
449data_pd_meas_info_author_fax
450    _name                      '_pd_meas_info_author_fax'
451    _category                    pd_meas_info
452    _type                        char
453    _list                        both
454    _list_reference            '_pd_meas_info_author_name'
455    _definition
456;              The fax number of the person who measured the data set. If
457               there is more than one person, this will be looped with
458               _pd_meas_info_author_name. The recommended style is
459               the international dialing prefix, followed by the area code in
460               parentheses, followed by the local number with no spaces.
461;
462
463data_pd_meas_info_author_name
464    _name                      '_pd_meas_info_author_name'
465    _category                    pd_meas_info
466    _type                        char
467    _list                        both
468    _definition
469;              The name of the person who measured the data set. The family
470               name(s), followed by a comma and including any dynastic
471               components, precedes the first name(s) or initial(s).
472               For more than one person use a loop to specify multiple values.
473;
474
475data_pd_meas_info_author_phone
476    _name                      '_pd_meas_info_author_phone'
477    _category                    pd_meas_info
478    _type                        char
479    _list                        both
480    _list_reference            '_pd_meas_info_author_name'
481    _definition
482;              The telephone number of the person who measured the data set.
483               If there is more than one person, this will be looped with
484               _pd_meas_info_author_name. The recommended style is
485               the international dialing prefix, followed by the area code in
486               parentheses, followed by the local number with no spaces.
487;
488
489data_pd_meas_intensity_
490    loop_ _name                '_pd_meas_intensity_total'
491                               '_pd_meas_intensity_background'
492                               '_pd_meas_intensity_container'
493                               '_pd_meas_intensity_monitor'
494    _category                    pd_data
495    _type                        numb
496    _type_conditions             esd
497    _list                        yes
498    _definition
499;              Intensity measurements at the measurement point (see
500               the definition of _pd_meas_2theta_).
501
502               The defined fields are:
503                 _pd_meas_intensity_total, scattering from the specimen
504                   (with background, specimen mounting or container
505                   scattering included);
506                 _pd_meas_intensity_background, scattering measured
507                   without a specimen, specimen mounting etc., often
508                   referred to as the instrument background;
509                 _pd_meas_intensity_container, the specimen container or
510                   mounting without a specimen, includes background;
511                 _pd_meas_intensity_monitor, intensity measured by an
512                   incident-beam monitor to calibrate the flux on the specimen.
513
514               Use these entries for measurements where intensity
515               values are not counts (use _pd_meas_counts_ for event-counting
516               measurements where the standard uncertainty is
517               estimated as the square root of the number of counts).
518
519               Corrections for background, detector dead time etc.,
520               should not have been made to these values. Instead use
521               _pd_proc_intensity_ for corrected diffractograms.
522
523               _pd_meas_units_of_intensity should be used to specify
524               the units of the intensity measurements.
525;
526
527data_pd_meas_number_of_points
528    _name                      '_pd_meas_number_of_points'
529    _category                    pd_meas_method
530    _type                        numb
531    _enumeration_range           1:
532    _definition
533;              The total number of points in the measured
534               diffractogram.
535;
536
537data_pd_meas_position
538    _name                      '_pd_meas_position'
539    _category                    pd_data
540    _type                        numb
541    _type_conditions             esd
542    _list                        yes
543    _units                       mm
544    _units_detail               'millimetres'
545    _definition
546;              A linear distance in millimetres corresponding to the
547               location where an intensity measurement is made.
548               Used for detectors where a distance measurement is made
549               as a direct observable, such as from a microdensitometer
550               trace from film or a strip chart recorder. This is an
551               alternative to _pd_meas_2theta_scan, which should only be
552               used for instruments that record intensities directly
553               against 2\q. For instruments where the position scale
554               is nonlinear, the data item _pd_meas_detector_id should
555               be used to record positions.
556
557               Calibration information, such as angle offsets or a
558               function to convert this distance to a 2\q angle
559               or d-space, should be supplied with the _pd_calib_ values.
560
561               Do not confuse this with the instrument geometry
562               descriptions given by _pd_instr_dist_.
563;
564
565data_pd_meas_rocking_angle
566    _name                      '_pd_meas_rocking_angle'
567    _category                    pd_data
568    _type                        numb
569    _list                        both
570    _units                       deg
571    _units_detail               'degrees'
572    _enumeration_range           0:360.0
573    _definition
574;              The angular range in degrees through which a sample is rotated
575               or oscillated during a measurement step
576               (see _pd_meas_rocking_axis).
577;
578
579data_pd_meas_rocking_axis
580    _name                      '_pd_meas_rocking_axis'
581    _category                    pd_meas_method
582    _type                        char
583    loop_ _enumeration           chi
584                                 omega
585                                 phi
586    _definition
587;              Description of the axis (or axes) used to rotate or rock the
588               specimen for better randomization of crystallites
589               (see _pd_meas_rocking_angle).
590;
591
592data_pd_meas_scan_method
593    _name                      '_pd_meas_scan_method'
594    _category                    pd_meas_method
595    _type                        char
596    loop_ _enumeration
597          _enumeration_detail    step    'step scan'
598                                 cont    'continuous scan'
599                                 tof     'time of flight'
600                                 disp    'energy dispersive'
601                                 fixed   'stationary detector'
602    _definition
603;              Code identifying the method for scanning reciprocal space.
604               The designation `fixed' should be used for measurements where
605               film, a stationary position-sensitive or area detector
606               or other non-moving detection mechanism is used to
607               measure diffraction intensities.
608;
609
610data_pd_meas_special_details
611    _name                      '_pd_meas_special_details'
612    _category                    pd_meas_method
613    _type                        char
614    _definition
615;              Special details of the diffraction measurement process.
616               Include information about source instability, degradation etc.
617               However, this item should not be used to record information
618               that can be specified in other _pd_meas_ entries.
619;
620
621data_pd_meas_step_count_time
622    _name                      '_pd_meas_step_count_time'
623    _category                    pd_data
624    _type                        numb
625    _type_conditions             esd
626    _list                        both
627    _units                       s
628    _units_detail               'seconds'
629    _enumeration_range           0.0:
630    _definition
631;              The count time in seconds for each intensity measurement.
632               If this value varies for different intensity measurements,
633               then this item will be placed in the loop with the
634               diffraction measurements. If a single fixed value is used,
635               it may be recorded outside the loop.
636;
637
638data_pd_meas_time_of_flight
639    _name                      '_pd_meas_time_of_flight'
640    _category                    pd_data
641    _type                        numb
642    _type_conditions             esd
643    _list                        yes
644    _units                       \ms
645    _units_detail               'microseconds'
646    _enumeration_range           0:
647    _definition
648;              Measured time in microseconds for time-of-flight neutron
649               measurements. Note that the flight distance may be
650               specified using _pd_instr_dist_ values.
651;
652
653data_pd_meas_units_of_intensity
654    _name                      '_pd_meas_units_of_intensity'
655    _category                    pd_meas_method
656    _type                        char
657    loop_ _example        'estimated from strip chart'
658                          'arbitrary, from film density'
659                          'counts, with automatic dead-time correction applied'
660    _definition
661;              Units for intensity measurements when _pd_meas_intensity_
662               is used. Note that use of 'counts' or 'counts per second'
663               here is strongly discouraged: convert the intensity
664               measurements to counts and use _pd_meas_counts_ and
665               _pd_meas_step_count_time instead of _pd_meas_intensity_.
666;
667
668#........................... Calibration Information
669
670data_pd_calib_[pd]
671    _name                       '_pd_calib_[pd]'
672    _category                     category_overview
673    _type                         null
674    loop_
675        _example
676        _example_detail
677#----------------------------------------------------------------------------
678;
679   _pd_calib_std_external_block_id
680               QuartzPlate|D500#1234-987|B.Toby|91-15-09|14:02
681   _pd_calib_std_external_name
682               'Arkansas Stone quartz plate'
683;
684;
685    Example 1.
686;
687;
688    _pd_calibration_conversion_eqn
689    ; 2\q~actual~ = 2\q~setting~ + arctan(
690      cos(P~1~)/{1/[P~0~ (CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)})
691    ;
692;
693;
694    Example 2 -
695                2\q~actual~ = 2\q~setting~ + arctan( cos(P~1~) / {1/[P~0~
696                  (CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)} ).
697
698                This allows for the calibration of 2\q for a linear
699                position-sensitive detector (PSD) where the PSD has been
700                set so that the 'centre channel' (CH~0~) is located at
701                2\q~setting~ as a function of the channel number (CC). In
702                addition to CH~0~, variables P~0~, P~1~ and P~2~ are
703                calibration constants, where P~0~ is the width of a PSD
704                channel in degrees, P~1~ is the angle of the PSD with respect
705                to the perpendicular and P~2~ is a quadratic term for
706                nonlinearities in the detector.
707;
708#----------------------------------------------------------------------------
709    _definition
710;              This section defines the parameters used for the calibration
711               of the instrument that are used directly or indirectly in the
712               interpretation of this data set. The information in this
713               section of the CIF should generally be written when the
714               intensities are first measured, but from then on should remain
715               unchanged. Loops may be used for calibration information that
716               differs by detector channel. The _pd_calibration_ items,
717               however, are never looped.
718;
719
720data_pd_calib_2theta_
721    loop_ _name                '_pd_calib_2theta_offset'
722                               '_pd_calib_2theta_off_point'
723                               '_pd_calib_2theta_off_min'
724                               '_pd_calib_2theta_off_max'
725    _category                    pd_calib
726    _type                        numb
727    _list                        both
728    _list_reference            '_pd_calib_detector_id'
729    _units                       deg
730    _units_detail               'degrees'
731    _enumeration_range           -180.0:180.0
732    _definition
733;              _pd_calib_2theta_offset defines an offset angle (in degrees)
734               used to calibrate 2\q (as defined in _pd_meas_2theta_).
735               Calibration is done by adding the offset:
736
737                    2\q~calibrated~ = 2\q~measured~ + 2\q~offset~
738
739               For cases where the _pd_calib_2theta_offset value is
740               not a constant, but rather varies with 2\q, a set
741               of offset values can be supplied in a loop. In this case,
742               the value where the offset has been determined can be
743               specified as _pd_calib_2theta_off_point. Alternatively, a
744               range where the offset is applicable can be specified using
745               _pd_calib_2theta_off_min and _pd_calib_2theta_off_max.
746;
747
748data_pd_calib_detector_id
749    _name                      '_pd_calib_detector_id'
750    _category                    pd_calib
751    _type                        char
752    _list                        yes
753    _list_mandatory              yes
754    _list_link_child           '_pd_meas_detector_id'
755    _definition
756;              A code which identifies the detector or channel number in a
757               position-sensitive, energy-dispersive or other multiple-detector
758               instrument. Note that this code should match the code name used
759               for _pd_meas_detector_id.
760;
761
762data_pd_calib_detector_response
763    _name                      '_pd_calib_detector_response'
764    _category                    pd_calib
765    _type                        numb
766    _list                        yes
767    _list_reference            '_pd_calib_detector_id'
768    _enumeration_range           0.0:
769    _definition
770;              A value that indicates the relative sensitivity of each
771               detector. This can compensate for differences in electronics,
772               size and collimation. Usually, one detector or the mean for
773               all detectors will be assigned the value of 1.
774;
775
776data_pd_calib_std_external_
777    loop_ _name                '_pd_calib_std_external_block_id'
778                               '_pd_calib_std_external_name'
779    _category                    pd_calib
780    _type                        char
781    _list                        both
782    _list_reference            '_pd_calib_detector_id'
783    _definition
784;              Identifies the data set used as an external standard for
785               the diffraction angle or the intensity calibrations.
786               *_name specifies the name of the material and
787               *_id the _pd_block_id for the CIF containing calibration
788               measurements. If more than one data set is used for
789               calibration, these fields may be looped.
790;
791
792data_pd_calib_std_internal_mass_%
793    _name                      '_pd_calib_std_internal_mass_%'
794    _category                    pd_calib
795    _type                        numb
796    _type_conditions             esd
797    _list                        both
798    _list_reference            '_pd_calib_detector_id'
799    _enumeration_range           0.0:100.0
800    _definition
801;              Per cent presence of the internal standard specified by the
802               data item _pd_calib_std_internal_name expressed as 100 times
803               the ratio of the amount of standard added to the original
804               sample mass.
805;
806
807data_pd_calib_std_internal_name
808    _name                      '_pd_calib_std_internal_name'
809    _category                    pd_calib
810    _type                        char
811    _list                        both
812    _list_reference            '_pd_calib_detector_id'
813    loop_ _example              'NIST 640a Silicon standard'
814                                'Al2O3'
815    _definition
816;              Identity of material(s) used as an internal intensity standard.
817;
818
819data_pd_calibration_conversion_eqn
820    _name                      '_pd_calibration_conversion_eqn'
821    _category                    pd_calibration
822    _type                        char
823    _example
824; 2\q~actual~ = 2\q~setting~ + arctan(
825             cos(P~1~) / {1/[P~0~ (CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)} )
826;
827    _definition
828;              The calibration function for converting a channel number
829               supplied in _pd_meas_detector_id for a position-sensitive
830               or energy-dispersive detector or the distance supplied in
831               _pd_meas_position to Q, energy, angle etc.
832               Use _pd_calib_std_external_ to define a pointer
833               to the file or data block containing the information used
834               to define this function.
835;
836
837data_pd_calibration_special_details
838    _name                      '_pd_calibration_special_details'
839    _category                    pd_calibration
840    _type                        char
841    _definition
842;              Description of how the instrument was
843               calibrated, particularly for instruments where
844               calibration information is used to make hardware
845               settings that would otherwise be invisible once data
846               collection is completed. Do not use this item to specify
847               information that can be specified using other _pd_calib_
848               items.
849;
850
851#............................ Specimen parameters
852
853data_pd_spec_[pd]
854    _name                       '_pd_spec_[pd]'
855    _category                     category_overview
856    _type                         null
857    loop_
858        _example
859        _example_detail
860#----------------------------------------------------------------------------
861;
862    _pd_spec_mounting               ?
863    _pd_spec_mount_mode             transmission
864    _pd_spec_orientation            horizontal
865    _pd_spec_preparation            ?
866;
867;
868    Example 1.
869;
870#----------------------------------------------------------------------------
871    _definition
872;              This section contains information about the specimen used
873               for measurement of the diffraction data set. Note that
874               information about the sample (the batch of material from which
875               the specimen was obtained) is specified in _pd_prep_.
876;
877
878data_pd_spec_description
879     _name                     '_pd_spec_description'
880     _category                   pd_spec
881     _type                       char
882     _definition
883;               A description of the specimen, such as the source of the
884                specimen, identification of standards, mixtures etc.
885;
886
887data_pd_spec_mount_mode
888    _name                      '_pd_spec_mount_mode'
889    _category                    pd_spec
890    _type                        char
891    loop_ _enumeration           reflection
892                                 transmission
893    _definition
894;              A code describing the beam path through the specimen.
895;
896
897data_pd_spec_mounting
898    _name                      '_pd_spec_mounting'
899    _category                    pd_spec
900    _type                        char
901    loop_ _example               'vanadium can with He exchange gas'
902                                 'quartz capillary'
903                                 'packed powder pellet'
904                                 'drifted powder on off-cut Si'
905                                 'drifted powder on Kapton film'
906    _definition
907;              A description of how the specimen is mounted.
908;
909
910data_pd_spec_orientation
911    _name                      '_pd_spec_orientation'
912    _category                    pd_spec
913    _type                        char
914    loop_ _enumeration           horizontal
915                                 vertical
916                                 both
917    _definition
918;              The orientation of the \w (\q) and 2\q axis.
919               Note that this axis is parallel to the specimen axial axis
920               and perpendicular to the plane containing the incident and
921               scattered beams.
922
923               Thus for a horizontal orientation, scattering
924               measurements are made in a plane perpendicular to the
925               ground (the 2\q axis is parallel to the ground);
926               for vertical orientation, scattering measurements are
927               made in a plane parallel with the ground (the 2\q axis
928               is perpendicular to the ground). `Both' is appropriate for
929               experiments where measurements are made in both planes,
930               for example using two-dimensional detectors.
931;
932
933data_pd_spec_preparation
934    _name                      '_pd_spec_preparation'
935    _category                    pd_spec
936    _type                        char
937    loop_ _example               'wet grinding in acetone'
938                              'sieved through a 44 micron (325 mesh/inch) sieve'
939                                 'spray dried in water with 1% clay'
940    _definition
941;              A description of the preparation steps for producing the
942               diffraction specimen from the sample. Include any procedures
943               related to grinding, sieving, spray drying etc. For
944               information relevant to how the sample is synthesized, use
945               the _pd_prep_ entries.
946;
947
948data_pd_spec_shape
949    _name                      '_pd_spec_shape'
950    _category                    pd_spec
951    _type                        char
952    loop_ _enumeration           cylinder
953                                 flat_sheet
954                                 irregular
955    _definition
956;              A code describing the specimen shape.
957;
958
959data_pd_spec_size_
960    loop_ _name                '_pd_spec_size_axial'
961                               '_pd_spec_size_equat'
962                               '_pd_spec_size_thick'
963    _category                    pd_spec
964    _type                        numb
965    _units                       mm
966    _units_detail               'millimetres'
967    _enumeration_range           0.0:
968    _definition
969;              The size of the specimen in three mutually perpendicular
970               directions in millimetres.
971               The perpendicular to the plane containing the incident
972               and scattered beam is the *_axial direction.
973               In transmission geometry, the scattering vector is parallel
974               to *_equat and in reflection geometry the scattering vector is
975               parallel to *_thick.
976
977;
978
979data_pd_spec_special_details
980    _name                      '_pd_spec_special_details'
981    _category                   pd_spec
982    _type                       char
983    _definition
984;              Descriptive information about the specimen that cannot be
985               included in other data items.
986;
987
988#............................ Instrument parameters
989
990data_pd_instr_[pd]
991    _name                       '_pd_instr_[pd]'
992    _category                     category_overview
993    _type                         null
994    loop_
995        _example
996        _example_detail
997#----------------------------------------------------------------------------
998;
999    _pd_instr_slit_eq_src/spec       1.
1000    _pd_instr_slit_eq_anal/detc      0.2
1001
1002    _pd_instr_geometry              Bragg-Brentano
1003    _pd_instr_monochr_post_spec     'graphite (0001)'
1004    _pd_instr_cons_illum_flag       no
1005;
1006;
1007    Example 1.
1008;
1009#----------------------------------------------------------------------------
1010    _definition
1011;              This section contains information relevant to the instrument
1012               used for the diffraction measurement. For most laboratories,
1013               very little of this information will change, so a standard file
1014               may be prepared and included with each data set.
1015
1016               Note that several definitions in the core CIF dictionary
1017               are relevant here. For example, use:
1018                 _diffrn_radiation_wavelength for the source wavelength,
1019                 _diffrn_radiation_type for the X-ray wavelength type,
1020                 _diffrn_source for the radiation source,
1021                 _diffrn_radiation_polarisn_ratio for the source polarization,
1022                 _diffrn_radiation_probe for the radiation type.
1023               For data sets measured with partially monochromatized radiation,
1024               for example, where both K\a~1~ and K\a~2~ are present, it is
1025               important that all wavelengths present are included in a
1026               loop_ using _diffrn_radiation_wavelength to define the
1027               wavelength and _diffrn_radiation_wavelength_wt to define the
1028               relative intensity of that wavelength. It is required that
1029               _diffrn_radiation_wavelength_id also be present in the
1030               wavelength loop. It may also be useful to
1031               create a "dummy" ID to use for labelling
1032               peaks/reflections where the K\a~1~ and K\a~2~ wavelengths are
1033               not resolved. Set _diffrn_radiation_wavelength_wt to be 0 for
1034               such a dummy ID.
1035
1036               In the _pd_instr_ definitions, the term monochromator refers
1037               to a primary beam (pre-specimen) monochromator and the term
1038               analyser refers to post-diffraction (post-specimen)
1039               monochromator.  The analyser may be fixed for specific
1040               wavelength or may be capable of being scanned.
1041
1042               For multiple-detector instruments it may be necessary to loop the
1043               *_anal/detc or *_spec/detc values (for  _pd_instr_dist_,
1044               _pd_instr_divg_, _pd_instr_slit_ and  _pd_instr_soller_) with
1045               the detector ID's (_pd_calib_detector_id).
1046
1047               It is strongly recommended that the core dictionary term
1048               _diffrn_radiation_probe (specifying the nature of the radiation
1049               used) is employed for all data sets.
1050;
1051
1052data_pd_instr_2theta_monochr_
1053    loop_ _name                 '_pd_instr_2theta_monochr_pre'
1054                                '_pd_instr_2theta_monochr_post'
1055    _category                    pd_instr
1056    _type                        numb
1057    _list                        both
1058    _units                       deg
1059    _units_detail               'degrees'
1060    _enumeration_range           -180.0:180.0
1061    _definition
1062;              The 2\q angle for a pre-specimen or post-specimen
1063               monochromator (see _pd_instr_monochr_pre_spec and
1064               _pd_instr_monochr_post_spec).
1065;
1066
1067data_pd_instr_beam_size_
1068    loop_ _name                '_pd_instr_beam_size_ax'
1069                               '_pd_instr_beam_size_eq'
1070    _category                    pd_data
1071    _type                        numb
1072    _enumeration_range           0.0:
1073    _units                       mm
1074    _units_detail               'millimetres'
1075    _definition
1076;              Axial and equatorial dimensions of the radiation beam
1077               at the specimen position (in millimetres).
1078               The perpendicular to the plane containing the incident
1079               and scattered beam is the axial (*_ax) direction.
1080;
1081
1082data_pd_instr_cons_illum_flag
1083    _name                      '_pd_instr_cons_illum_flag'
1084    _category                    pd_instr
1085    _type                        char
1086    loop_ _enumeration           yes  no
1087    _definition
1088;              Use 'yes' for instruments where the divergence slit is
1089               \q-compensated to yield a constant illumination length
1090               (also see _pd_instr_cons_illum_len).
1091
1092               For other flat-plate instruments, where the illumination
1093               length changes with 2\q, specify 'no'. Note that
1094               if the length is known, it may be specified using
1095               _pd_instr_var_illum_len.
1096;
1097
1098data_pd_instr_cons_illum_len
1099    _name                      '_pd_instr_cons_illum_len'
1100    _category                    pd_instr
1101    _type                        numb
1102    _enumeration_range           0.0:
1103    _units                       mm
1104    _units_detail               'millimetres'
1105    _definition
1106;              Length of the specimen that is illuminated by the radiation
1107               source (in millimetres).
1108
1109               Use _pd_instr_cons_illum_len for instruments where
1110               the illumination length does not vary with 2\q, by
1111               adjustment of the divergence slits (sometimes known
1112               as \q-compensated slits).
1113               Use _pd_instr_var_illum_len for instruments where
1114               the illuminated length of the specimen has been
1115               characterized as a function of 2\q, most commonly true
1116               with a fixed divergence slit.
1117;
1118
1119data_pd_instr_dist_
1120    loop_ _name                '_pd_instr_dist_src/mono'
1121                               '_pd_instr_dist_mono/spec'
1122                               '_pd_instr_dist_src/spec'
1123                               '_pd_instr_dist_spec/anal'
1124                               '_pd_instr_dist_anal/detc'
1125                               '_pd_instr_dist_spec/detc'
1126    _category                    pd_instr
1127    _type                        numb
1128    _units                       mm
1129    _units_detail               'millimetres'
1130    _enumeration_range           0.0:
1131    _list                        both
1132    _definition
1133;              Specifies distances in millimetres for the instrument geometry:
1134                 *_src/mono, the distance from the radiation source
1135                     to the monochromator;
1136                 *_mono/spec, the distance from the monochromator to
1137                     the specimen;
1138                 *_src/spec, the distance from the radiation source
1139                     to the specimen;
1140                 *_spec/anal, the distance from the specimen to the
1141                     analyser;
1142                 *_anal/detc, the distance from the analyser to the
1143                     detector;
1144                 *_spec/detc, the distance from the specimen to the
1145                     detector.
1146
1147               Note that *_src/spec is used in place of *_src/mono and
1148               *_mono/spec if there is no monochromator in use, and
1149               *_spec/detc is used in place of *_spec/anal and *_anal/detc
1150               if there is no analyser in use.
1151;
1152
1153data_pd_instr_divg_ax_
1154    loop_ _name                '_pd_instr_divg_ax_src/mono'
1155                               '_pd_instr_divg_ax_mono/spec'
1156                               '_pd_instr_divg_ax_src/spec'
1157                               '_pd_instr_divg_ax_spec/anal'
1158                               '_pd_instr_divg_ax_anal/detc'
1159                               '_pd_instr_divg_ax_spec/detc'
1160    _category                    pd_instr
1161    _type                        numb
1162    _enumeration_range           0.0:
1163    _units                       deg
1164    _units_detail               'degrees'
1165    _list                        both
1166    _definition
1167;              Describes collimation in the axial direction
1168               (perpendicular to the plane containing the incident
1169               and diffracted beams) for the instrument.
1170               Values are the maximum divergence angles in
1171               degrees, as limited by slits or beamline optics
1172               other than Soller slits (see _pd_instr_soller_ax_):
1173                 *_src/mono, collimation between the radiation source
1174                     and the monochromator;
1175                 *_mono/spec, collimation between the monochromator and
1176                     the specimen;
1177                 *_src/spec, collimation between the radiation source
1178                     and the specimen;
1179                 *_spec/anal, collimation between the specimen and the
1180                     analyser;
1181                 *_anal/detc, collimation between the analyser and the
1182                     detector;
1183                 *_spec/detc, collimation between the specimen and the
1184                     detector.
1185
1186               Note that *_src/spec is used in place of *_src/mono and
1187               *_mono/spec if there is no monochromator in use, and
1188               *_spec/detc is used in place of *_spec/anal and *_anal/detc
1189               if there is no analyser in use.
1190;
1191
1192data_pd_instr_divg_eq_
1193    loop_ _name                '_pd_instr_divg_eq_src/mono'
1194                               '_pd_instr_divg_eq_mono/spec'
1195                               '_pd_instr_divg_eq_src/spec'
1196                               '_pd_instr_divg_eq_spec/anal'
1197                               '_pd_instr_divg_eq_anal/detc'
1198                               '_pd_instr_divg_eq_spec/detc'
1199    _category                    pd_instr
1200    _type                        numb
1201    _enumeration_range           0.0:
1202    _units                       deg
1203    _units_detail               'degrees'
1204    _list                        both
1205    _definition
1206;              Describes collimation in the equatorial plane (the plane
1207               containing the incident and diffracted beams) for
1208               the instrument. Values are the maximum divergence angles in
1209               degrees, as limited by slits or beamline optics
1210               other than Soller slits (see _pd_instr_soller_eq_):
1211                 *_src/mono, collimation between the radiation source
1212                     and the monochromator;
1213                 *_mono/spec, collimation between the monochromator and
1214                     the specimen;
1215                 *_src/spec, collimation between the radiation source
1216                     and the specimen;
1217                 *_spec/anal, collimation between the specimen and the
1218                     analyser;
1219                 *_anal/detc, collimation between the analyser and the
1220                     detector;
1221                 *_spec/detc, collimation between the specimen and the
1222                     detector.
1223
1224               Note that *_src/spec is used in place of *_src/mono and
1225               *_mono/spec if there is no monochromator in use, and
1226               *_spec/detc is used in place of *_spec/anal and *_anal/detc
1227               if there is no analyser in use.
1228;
1229
1230data_pd_instr_geometry
1231    _name                      '_pd_instr_geometry'
1232    _category                    pd_instr
1233    _type                        char
1234    loop_ _example        Bragg-Brentano
1235                          Guinier
1236;                         Parallel-beam non-focusing optics with
1237                          channel-cut monochromator and linear
1238                          position-sensitive detector
1239;
1240    _definition
1241;              A description of the diffractometer type or geometry.
1242;
1243
1244data_pd_instr_location
1245    _name                      '_pd_instr_location'
1246    _category                    pd_instr
1247    _type                        char
1248    _example         'SEPD diffractometer, IPNS, Argonne National Lab (USA)'
1249    _definition
1250;              The name and location of the instrument where measurements
1251               were made. This is used primarily to identify data sets
1252               measured away from the author's home facility, at shared
1253               resources such as a reactor or spallation source.
1254;
1255
1256data_pd_instr_monochr_
1257    loop_ _name                 '_pd_instr_monochr_pre_spec'
1258                                '_pd_instr_monochr_post_spec'
1259    _category                    pd_instr
1260    _type                        char
1261    _list                        both
1262    loop_ _example              'Zr filter'   'Ge 220'   'none'
1263                                'equatorial mounted graphite (0001)'
1264                                'Si (111), antiparallel'
1265    _definition
1266;              Indicates the method used to obtain monochromatic radiation.
1267               Use _pd_instr_monochr_pre_spec to describe the primary beam
1268               monochromator (pre-specimen monochromation). Use
1269               _pd_instr_monochr_post_spec to specify the
1270               post-diffraction analyser (post-specimen monochromation).
1271
1272               When a monochromator crystal is used, the material and the
1273               indices of the Bragg reflection are specified.
1274
1275               Note that monochromators may have either 'parallel' or
1276               'antiparallel' orientation. It is assumed that the
1277               geometry is parallel unless specified otherwise.
1278               In a parallel geometry, the position of the monochromator
1279               allows the incident beam and the final post-specimen
1280               and post-monochromator beam to be as close to parallel
1281               as possible. In a parallel geometry, the diffracting
1282               planes in the specimen and monochromator will be parallel
1283               when 2\q~monochromator~ is equal to 2\q~specimen~.
1284               For further discussion see R. Jenkins & R. Snyder (1996).
1285               Introduction to X-ray Powder Diffraction,
1286               pp. 164-165. New York: Wiley.
1287;
1288
1289data_pd_instr_slit_ax_
1290    loop_ _name                '_pd_instr_slit_ax_src/mono'
1291                               '_pd_instr_slit_ax_mono/spec'
1292                               '_pd_instr_slit_ax_src/spec'
1293                               '_pd_instr_slit_ax_spec/anal'
1294                               '_pd_instr_slit_ax_anal/detc'
1295                               '_pd_instr_slit_ax_spec/detc'
1296    _category                    pd_instr
1297    _type                        numb
1298    _enumeration_range           0.0:
1299    _units                       mm
1300    _units_detail               'millimetres'
1301    _list                        both
1302    _definition
1303;              Describes collimation in the axial direction
1304               (perpendicular to the plane containing the incident
1305               and diffracted beams) for the instrument as a slit width
1306               (as opposed to a divergence angle).
1307               Values are the width of the slit (in millimetres) defining:
1308                 *_src/mono, collimation between the radiation source
1309                     and the monochromator;
1310                 *_mono/spec, collimation between the monochromator and
1311                     the specimen;
1312                 *_src/spec, collimation between the radiation source
1313                     and the specimen;
1314                 *_spec/anal, collimation between the specimen and the
1315                     analyser;
1316                 *_anal/detc, collimation between the analyser and the
1317                     detector;
1318                 *_spec/detc, collimation between the specimen and the
1319                     detector.
1320
1321               Note that *_src/spec is used in place of *_src/mono and
1322               *_mono/spec if there is no monochromator in use, and
1323               *_spec/detc is used in place of *_spec/anal and *_anal/detc
1324               if there is no analyser in use.
1325;
1326
1327data_pd_instr_slit_eq_
1328    loop_ _name                '_pd_instr_slit_eq_src/mono'
1329                               '_pd_instr_slit_eq_mono/spec'
1330                               '_pd_instr_slit_eq_src/spec'
1331                               '_pd_instr_slit_eq_spec/anal'
1332                               '_pd_instr_slit_eq_anal/detc'
1333                               '_pd_instr_slit_eq_spec/detc'
1334    _category                    pd_instr
1335    _type                        numb
1336    _enumeration_range           0.0:
1337    _units                       mm
1338    _units_detail               'millimetres'
1339    _list                        both
1340    _definition
1341;              Describes collimation in the equatorial plane (the plane
1342               containing the incident and diffracted beams) for the
1343               instrument as a slit width (as opposed to a divergence angle).
1344               Values are the width of the slit (in millimetres) defining:
1345                 *_src/mono, collimation between the radiation source
1346                     and the monochromator;
1347                 *_mono/spec, collimation between the monochromator and
1348                     the specimen;
1349                 *_src/spec, collimation between the radiation source
1350                     and the specimen;
1351                 *_spec/anal, collimation between the specimen and the
1352                     analyser;
1353                 *_anal/detc, collimation between the analyser and the
1354                     detector;
1355                 *_spec/detc, collimation between the specimen and the
1356                     detector.
1357
1358               Note that *_src/spec is used in place of *_src/mono and
1359               *_mono/spec if there is no monochromator in use, and
1360               *_spec/detc is used in place of *_spec/anal and
1361               *_anal/detc if there is no analyser in use.
1362;
1363
1364data_pd_instr_soller_ax_
1365    loop_ _name                '_pd_instr_soller_ax_src/mono'
1366                               '_pd_instr_soller_ax_mono/spec'
1367                               '_pd_instr_soller_ax_src/spec'
1368                               '_pd_instr_soller_ax_spec/anal'
1369                               '_pd_instr_soller_ax_anal/detc'
1370                               '_pd_instr_soller_ax_spec/detc'
1371    _category                    pd_instr
1372    _type                        numb
1373    _enumeration_range           0.0:
1374    _units                       deg
1375    _units_detail               'degrees'
1376    _list                        both
1377    _definition
1378;              Describes collimation in the axial direction
1379               (perpendicular to the plane containing the incident
1380               and diffracted beams) for the instrument.
1381               Values are the maximum divergence angles in
1382               degrees, as limited by Soller slits located thus:
1383                 *_src/mono, collimation between the radiation source
1384                     and the monochromator;
1385                 *_mono/spec, collimation between the monochromator and
1386                     the specimen;
1387                 *_src/spec, collimation between the radiation source
1388                     and the specimen;
1389                 *_spec/anal, collimation between the specimen and the
1390                     analyser;
1391                 *_anal/detc, collimation between the analyser and the
1392                     detector;
1393                 *_spec/detc, collimation between the specimen and the
1394                     detector.
1395
1396               Note that *_src/spec is used in place of *_src/mono and
1397               *_mono/spec if there is no monochromator in use, and
1398               *_spec/detc is used in place of *_spec/anal and
1399               *_anal/detc if there is no analyser in use.
1400;
1401
1402data_pd_instr_soller_eq_
1403    loop_ _name                '_pd_instr_soller_eq_src/mono'
1404                               '_pd_instr_soller_eq_mono/spec'
1405                               '_pd_instr_soller_eq_src/spec'
1406                               '_pd_instr_soller_eq_spec/anal'
1407                               '_pd_instr_soller_eq_anal/detc'
1408                               '_pd_instr_soller_eq_spec/detc'
1409    _category                    pd_instr
1410    _type                        numb
1411    _enumeration_range           0.0:
1412    _units                       deg
1413    _units_detail               'degrees'
1414    _list                        both
1415    _definition
1416;              Describes collimation in the equatorial plane (the plane
1417               containing the incident and diffracted beams) for
1418               the instrument. Values are the maximum divergence angles in
1419               degrees, as limited by Soller slits located thus:
1420                 *_src/mono, collimation between the radiation source
1421                     and the monochromator;
1422                 *_mono/spec, collimation between the monochromator and
1423                     the specimen;
1424                 *_src/spec, collimation between the radiation source
1425                     and the specimen;
1426                 *_spec/anal, collimation between the specimen and the
1427                     analyser;
1428                 *_anal/detc, collimation between the analyser and the
1429                     detector;
1430                 *_spec/detc, collimation between the specimen and the
1431                     detector.
1432
1433               Note that *_src/spec is used in place of *_src/mono and
1434               *_mono/spec if there is no monochromator in use, and
1435               *_spec/detc is used in place of *_spec/anal and
1436               *_anal/detc if there is no analyser in use.
1437;
1438
1439data_pd_instr_source_size_
1440    loop_ _name                '_pd_instr_source_size_ax'
1441                               '_pd_instr_source_size_eq'
1442    _category                    pd_instr
1443    _type                        numb
1444    _enumeration_range           0.0:
1445    _units                       mm
1446    _units_detail               'millimetres'
1447    _definition
1448;              Axial and equatorial intrinsic dimensions
1449               of the radiation source (in millimetres).
1450               The perpendicular to the plane containing the incident
1451               and scattered beam is the axial (*_ax) direction.
1452;
1453
1454data_pd_instr_special_details
1455    _name                      '_pd_instr_special_details'
1456    _category                    pd_instr
1457    _type                        char
1458    _definition
1459;              A brief description of the instrument giving
1460               details that cannot be given in other
1461               _pd_instr_ entries.
1462;
1463
1464data_pd_instr_var_illum_len
1465    _name                      '_pd_instr_var_illum_len'
1466    _category                    pd_data
1467    _list                        yes
1468    _type                        numb
1469    _enumeration_range           0.0:
1470    _units                       mm
1471    _units_detail               'millimetres'
1472    _definition
1473;              Length of the specimen that is illuminated by the radiation
1474               source (in millimetres) for instruments where
1475               the illumination length varies with 2\q (fixed
1476               divergence slits). The _pd_instr_var_illum_len
1477               values should be included in the same loop as the
1478               intensity measurements (_pd_meas_).
1479
1480               See _pd_instr_cons_illum_len for instruments where
1481               the divergence slit is \q-compensated to yield a
1482               constant illumination length.
1483;
1484
1485#............................. Processed Diffractogram
1486
1487data_pd_proc_[pd]
1488    _name                       '_pd_proc_[pd]'
1489    _category                     category_overview
1490    _type                         null
1491    _definition
1492;              This section contains the diffraction data set after processing
1493               and application of correction terms. If the data set is
1494               reprocessed, this section may be replaced (with the addition of
1495               a new _pd_block_id entry).
1496;
1497
1498data_pd_proc_2theta_corrected
1499    _name                      '_pd_proc_2theta_corrected'
1500    _category                    pd_data
1501    _type                        numb
1502    _list                        yes
1503    _units                       deg
1504    _units_detail               'degrees'
1505    _enumeration_range           -180.0:180.0
1506    _definition
1507;              The 2\q diffraction angle in degrees of an intensity
1508               measurement where 2\q is not constant. Used if
1509               corrections such as for nonlinearity, zero offset etc.
1510               have been applied to the _pd_meas_2theta_ values or if
1511               2\q values are computed. If the 2\q values
1512               are evenly spaced, _pd_proc_2theta_range_min,
1513               _pd_proc_2theta_range_max and _pd_proc_2theta_range_inc
1514               may be used to specify the 2\q values.
1515;
1516
1517data_pd_proc_2theta_range_
1518    loop_ _name                '_pd_proc_2theta_range_min'
1519                               '_pd_proc_2theta_range_max'
1520                               '_pd_proc_2theta_range_inc'
1521    _category                    pd_proc_info
1522    _type                        numb
1523    _units                       deg
1524    _units_detail               'degrees'
1525    _enumeration_range           -180.0:180.0
1526    _definition
1527;              The range of 2\q diffraction angles in degrees for the
1528               measurement of intensities. These may be used in place of the
1529               _pd_proc_2theta_corrected values, or in the case of white-beam
1530               experiments it will define the fixed 2\q value.
1531;
1532
1533data_pd_proc_d_spacing
1534    _name                      '_pd_proc_d_spacing'
1535    _category                    pd_data
1536    _type                        numb
1537    _list                        yes
1538    _enumeration_range           0.0:
1539    _units                       A
1540    _units_detail               'angstroms'
1541    _definition
1542;              d-spacing corresponding to an intensity point
1543               from Bragg's law, d = \l/(2 sin\q), in units of angstroms.
1544;
1545
1546data_pd_proc_energy_
1547    loop_ _name                '_pd_proc_energy_incident'
1548                               '_pd_proc_energy_detection'
1549    _category                    pd_data
1550    _type                        numb
1551    _list                        both
1552    _units                       eV
1553    _units_detail               'electron volts'
1554    _enumeration_range           0.0:
1555    _definition
1556;              Incident energy in electronvolts of the source computed
1557               from secondary calibration information (time-of-flight
1558               and synchrotron data).
1559               Detection energy in electronvolts selected by the analyser,
1560               if not the same as the incident energy (triple-axis or
1561               energy-dispersive data). This may be a single value or may
1562               vary for each data point (triple-axis and time-of-flight data).
1563;
1564
1565data_pd_proc_info_author_address
1566    _name                      '_pd_proc_info_author_address'
1567    _category                    pd_proc_info
1568    _type                        char
1569    _list                        both
1570    _list_reference            '_pd_proc_info_author_name'
1571    _definition
1572;               The address of the person who processed the data.
1573                If there is more than one person, this will be looped with
1574                _pd_proc_info_author_name.
1575;
1576
1577data_pd_proc_info_author_email
1578    _name                      '_pd_proc_info_author_email'
1579    _category                    pd_proc_info
1580    _type                        char
1581    _list                        both
1582    _list_reference            '_pd_proc_info_author_name'
1583    _definition
1584;               The e-mail address of the person who processed the
1585                data.  If there is more than one person, this will be looped
1586                with _pd_proc_info_author_name.
1587;
1588
1589data_pd_proc_info_author_fax
1590    _name                      '_pd_proc_info_author_fax'
1591    _category                    pd_proc_info
1592    _type                        char
1593    _list                        both
1594    _list_reference            '_pd_proc_info_author_name'
1595    _definition
1596;               The fax number of the person who processed the data.
1597                If there is more than one person, this will be looped with
1598                _pd_proc_info_author_name. The recommended style is
1599                the international dialing prefix, followed by the area code in
1600                parentheses, followed by the local number with no spaces.
1601;
1602
1603data_pd_proc_info_author_name
1604    _name                      '_pd_proc_info_author_name'
1605    _category                    pd_proc_info
1606    _type                        char
1607    _list                        both
1608    _definition
1609;               The name of the person who processed the data, if different
1610                from the person(s) who measured the data set. The family
1611                name(s), followed by a comma and including any dynastic
1612                components, precedes the first name(s) or initial(s). For
1613                more than one person use a loop to specify multiple values.
1614;
1615
1616data_pd_proc_info_author_phone
1617    _name                      '_pd_proc_info_author_phone'
1618    _category                    pd_proc_info
1619    _type                        char
1620    _list                        both
1621    _list_reference            '_pd_proc_info_author_name'
1622    _definition
1623;               The telephone number of the person who processed the data.
1624                If there is more than one person, this will be looped
1625                with _pd_proc_info_author_name. The recommended style is
1626                the international dialing prefix, followed by the area code in
1627                parentheses, followed by the local number with no spaces.
1628;
1629
1630data_pd_proc_info_data_reduction
1631    _name                      '_pd_proc_info_data_reduction'
1632    _category                    pd_proc_info
1633    _type                        char
1634    _definition
1635;              Description of the processing steps applied in the data-reduction
1636               process (background subtraction, \a-2 stripping, smoothing
1637               etc.). Include details of the program(s) used etc.
1638;
1639
1640data_pd_proc_info_datetime
1641    _name                      '_pd_proc_info_datetime'
1642    _category                    pd_proc_info
1643    _type                        char
1644    _list                        both
1645    _example                     1990-07-13T14:40
1646    _definition
1647;              Date(s) and time(s) when the data set was processed.
1648               May be looped if multiple processing steps were used.
1649
1650               Dates and times should be specified in the standard CIF
1651               format 'yyyy-mm-ddThh:mm:ss+zz'. Use of seconds and a
1652               time zone is optional, but use of hours and minutes is
1653               strongly encouraged.
1654;
1655
1656data_pd_proc_info_excluded_regions
1657    _name                      '_pd_proc_info_excluded_regions'
1658    _category                    pd_proc_info
1659    _type                        char
1660    _example                    '20 to 21 degrees unreliable due to beam dump'
1661    _definition
1662;              Description of regions in the diffractogram excluded
1663               from processing along with a justification of why the
1664               data points were not used.
1665;
1666
1667data_pd_proc_info_special_details
1668    _name                      '_pd_proc_info_special_details'
1669    _category                    pd_proc_info
1670    _type                        char
1671    _definition
1672;              Detailed description of any non-routine processing steps
1673               applied due to any irregularities in this particular data set.
1674;
1675
1676data_pd_proc_intensity_
1677    loop_ _name                '_pd_proc_intensity_net'
1678                               '_pd_proc_intensity_total'
1679                               '_pd_proc_intensity_bkg_calc'
1680                               '_pd_proc_intensity_bkg_fix'
1681                               '_pd_proc_intensity_incident'
1682                               '_pd_proc_intensity_norm'
1683    _category                    pd_data
1684    _type                        numb
1685    _type_conditions             esd
1686    _list                        yes
1687    _enumeration_range           0.0:
1688    _definition
1689;              _pd_proc_intensity_net contains intensity values for the
1690               processed diffractogram for each data point (see
1691               _pd_proc_2theta_, _pd_proc_wavelength etc.) after
1692               correction and normalization factors have been applied
1693               (in contrast to _pd_meas_counts_ values, which are
1694               uncorrected).
1695
1696               _pd_proc_intensity_total contains intensity values for the
1697               processed diffractogram for each data point where
1698               background, normalization and other corrections have not
1699               been applied.
1700
1701               Inclusion of s.u.'s for these values is strongly recommended.
1702
1703               _pd_proc_intensity_bkg_calc is intended to contain the
1704               background intensity for every data point where the
1705               background function has been fitted or estimated (for example, in
1706               all Rietveld and profile fits).
1707
1708               If the background is estimated for a limited number of points
1709               and the calculated background is then extrapolated from
1710               these fixed points, indicate the background values for
1711               these points with _pd_proc_intensity_bkg_fix. Use a value
1712               of '.' for data points where a fixed background has not
1713               been defined. The extrapolated background at every point
1714               may be specified using _pd_proc_intensity_bkg_calc.
1715
1716               Background values should be on the same scale as the
1717               _pd_proc_intensity_net values. Thus normalization and
1718               correction factors should be applied before
1719               background subtraction (or should be applied to the
1720               background values equally).
1721
1722               If the intensities have been corrected for a variation of the
1723               incident intensity as a function of a data-collection
1724               variable (examples: source fluctuations in synchrotrons,
1725               \q-compensated slits in conventional diffractometers,
1726               spectral corrections for white-beam experiments), the
1727               correction function should be specified as
1728               _pd_proc_intensity_incident. The normalization should be
1729               specified in _pd_proc_intensity_incident as a value to be
1730               used to divide the measured intensities to obtained the
1731               normalized diffractogram. Thus, the
1732               _pd_proc_intensity_incident values should increase as the
1733               incident flux is increased.
1734
1735               The other normalization factors applied to the data set (for
1736               example, Lp corrections, compensation for variation in
1737               counting time) may be specified in _pd_proc_intensity_norm.
1738               The function should be specified as the one used to divide the
1739               measured intensities.
1740;
1741
1742data_pd_proc_number_of_points
1743    _name                      '_pd_proc_number_of_points'
1744    _category                    pd_proc_info
1745    _type                        numb
1746    _enumeration_range           1:
1747    _definition
1748;              The total number of data points in the processed diffractogram.
1749;
1750
1751data_pd_proc_recip_len_Q
1752    _name                      '_pd_proc_recip_len_Q'
1753    _category                    pd_data
1754    _type                        numb
1755    _list                        yes
1756    _enumeration_range           0.0:
1757    _units                       A^-1^
1758    _units_detail               'reciprocal angstroms'
1759    _definition
1760;              Length in reciprocal space (|Q|= 2\p/d) corresponding to
1761               an intensity point. Units are inverse angstroms.
1762;
1763
1764data_pd_proc_wavelength
1765    _name                      '_pd_proc_wavelength'
1766    _category                    pd_data
1767    _type                        numb
1768    _list                        both
1769    _enumeration_range           0.0:
1770    _units                       A
1771    _units_detail               'Angstroms'
1772    _definition
1773;              Wavelength in angstroms for the incident radiation as
1774               computed from secondary calibration information. This will
1775               be most appropriate for time-of-flight and synchrotron
1776               measurements. This will be a single value for
1777               continuous-wavelength methods or may vary for each data point
1778               and be looped with the intensity values for energy-dispersive
1779               measurements.
1780;
1781
1782#......................... Least-squares (Profile/Rietveld fit) parameters
1783
1784data_pd_proc_ls_[pd]
1785    _name                       '_pd_proc_ls_[pd]'
1786    _category                     category_overview
1787    _type                         null
1788
1789    _definition
1790;              This section is used to define parameters relevant to a
1791               least-squares fit to a powder diffractogram, using a Rietveld
1792               or other full-profile (e.g. Pawley or Le Bail methods) fit.
1793
1794               Note that values in this section refer to full-pattern fitting.
1795               Use the appropriate items for single-crystal analyses from the
1796               core CIF dictionary for structure refinements using diffraction
1797               intensities estimated from a powder diffractogram by
1798               pattern-decomposition methods. Also note that many entries in
1799               the core _refine_ls_ entries may also be useful (for example
1800               _refine_ls_shift/su_*).
1801;
1802
1803data_pd_proc_ls_background_function
1804    _name                      '_pd_proc_ls_background_function'
1805    _category                    pd_proc_ls
1806    _type                        char
1807    _definition
1808;              Description of the background treatment mechanism used to
1809               fit the data set.
1810
1811               For refinements where the background is computed as a
1812               function that is fitted to minimize the difference between
1813               the observed and calculated patterns, it is
1814               recommended that in addition to a description of the
1815               function (e.g. Chebychev polynomial), the actual equation(s)
1816               used are included in TeX, or a programming language such
1817               as Fortran or C. Include also the values used for the
1818               coefficients used in the background function with their
1819               s.u.'s. The background values for each data point
1820               computed from the function should be specified in
1821               _pd_proc_intensity_bkg_calc.
1822
1823               If background correction is performed using extrapolation
1824               from a set of points at fixed locations, these points
1825               should be defined using _pd_proc_intensity_bkg_fix, and
1826               _pd_proc_ls_background_function should indicate the
1827               extrapolation method (linear extrapolation, spline etc.).
1828               _pd_proc_ls_background_function should also indicate how the
1829               points were determined (automatically, by visual estimation
1830               etc.) and whether the values were refined to improve the
1831               agreement. The extrapolated background intensity value for
1832               each data point should be specified in
1833               _pd_proc_intensity_bkg_calc.
1834;
1835
1836data_pd_proc_ls_peak_cutoff
1837    _name                      '_pd_proc_ls_peak_cutoff'
1838    _category                    pd_proc_ls
1839    _type                        numb
1840    _definition
1841;              Describes where peak-intensity computation is
1842               discontinued as a fraction of the intensity of the
1843               peak at maximum. Thus for a value of 0.005, the
1844               tails of a diffraction peak are neglected
1845               after the intensity has dropped below 0.5% of the
1846               diffraction intensity at the maximum.
1847;
1848
1849data_pd_proc_ls_pref_orient_corr
1850    _name                      '_pd_proc_ls_pref_orient_corr'
1851    _category                    pd_proc_ls
1852    _type                        char
1853    _definition
1854;              Description of the preferred-orientation correction if
1855               such a correction is used. Omitting this entry
1856               implies that no preferred-orientation correction
1857               has been used. If a function form is used, it is
1858               recommended that the actual equation in TeX, or a
1859               programming language, is used to specify the function as
1860               well as a giving a description. Include the value(s) used
1861               for the correction with s.u.'s.
1862;
1863
1864data_pd_proc_ls_prof_
1865    loop_ _name                 '_pd_proc_ls_prof_R_factor'
1866                                '_pd_proc_ls_prof_wR_factor'
1867                                '_pd_proc_ls_prof_wR_expected'
1868    _category                    pd_proc_ls
1869    _type                        numb
1870    _enumeration_range           0.0:
1871    _definition
1872;              Rietveld/profile fit R factors.
1873
1874               Note that the R factor computed for Rietveld refinements
1875               using the extracted reflection intensity values (often
1876               called the Rietveld or Bragg R factor, R~B~) is not properly
1877               a profile R factor. This R factor may be specified using
1878               _refine_ls_R_I_factor. (Some authors report
1879               _refine_ls_R_Fsqd_factor or _refine_ls_R_factor_all
1880               as the Rietveld or Bragg R factor. While it is appropriate
1881               to compute and report any or all of these R factors,
1882               the names "Rietveld or Bragg R factor" refer strictly to
1883               _refine_ls_R_I_factor.)
1884
1885              _pd_proc_ls_prof_R_factor, often called R~p~, is an
1886                unweighted fitness metric for the agreement between the
1887                observed and computed diffraction patterns.
1888                   R~p~ = sum~i~ | I~obs~(i) - I~calc~(i) |
1889                          / sum~i~ ( I~obs~(i) )
1890              _pd_proc_ls_prof_wR_factor, often called R~wp~, is a
1891                weighted fitness metric for the agreement between the
1892                observed and computed diffraction patterns.
1893                  R~wp~ = SQRT {
1894                           sum~i~ ( w(i) [ I~obs~(i) - I~calc~(i) ]^2^ )
1895                           / sum~i~ ( w(i) [I~obs~(i)]^2^ ) }
1896
1897              _pd_proc_ls_prof_wR_expected, sometimes called the
1898                theoretical R~wp~ or R~exp~, is a weighted fitness metric for
1899                the statistical precision of the data set. For an idealized fit,
1900                where all deviations between the observed intensities and
1901                those computed from the model are due to statistical
1902                fluctuations, the observed R~wp~ should match the expected
1903                R factor. In reality, R~wp~ will always be higher than
1904                R~exp~.
1905                  R~exp~ = SQRT {
1906                                 (n - p)  / sum~i~ ( w(i) [I~obs~(i)]^2^ ) }
1907
1908                Note that in the above equations,
1909                   w(i) is the weight for the ith data point (see
1910                        _pd_proc_ls_weight).
1911                   I~obs~(i) is the observed intensity for the ith data
1912                        point, sometimes referred to as y~i~(obs) or
1913                        y~oi~. (See _pd_meas_counts_total,
1914                        _pd_meas_intensity_total or _pd_proc_intensity_total.)
1915                   I~calc~(i) is the computed intensity for the ith data
1916                        point with background and other corrections
1917                        applied to match the scale of the observed data set,
1918                        sometimes referred to as y~i~(calc) or
1919                        y~ci~. (See _pd_calc_intensity_total.)
1920                   n is the total number of data points (see
1921                        _pd_proc_number_of_points) less the number of
1922                        data points excluded from the refinement.
1923                   p is the total number of refined parameters.
1924;
1925
1926data_pd_proc_ls_profile_function
1927    _name                      '_pd_proc_ls_profile_function'
1928    _category                    pd_proc_ls
1929    _type                        char
1930    _definition
1931;              Description of the profile function used to
1932               fit the data set. If a function form is used, it is
1933               recommended that the actual equation in TeX, or a
1934               programming language, is used to specify the function as
1935               well as giving a description. Include the values used
1936               for the profile-function coefficients and their s.u.'s.
1937;
1938
1939data_pd_proc_ls_special_details
1940    _name                      '_pd_proc_ls_special_details'
1941    _category                    pd_proc_ls
1942    _type                        char
1943    _definition
1944;              Additional characterization information relevant to
1945               non-routine steps used for refinement of a structural model
1946               that cannot be specified elsewhere.
1947;
1948
1949data_pd_proc_ls_weight
1950    _name                      '_pd_proc_ls_weight'
1951    _category                    pd_data
1952    _type                        numb
1953    _list                        yes
1954    _enumeration_range           0:
1955    _definition
1956;              Weight applied to each profile point. These values
1957               may be omitted if the weights are 1/u^2^, where
1958               u is the s.u. for the _pd_proc_intensity_net values.
1959
1960               A weight value of zero is used to indicate a data
1961               point not used for refinement (see
1962               _pd_proc_info_excluded_regions).
1963;
1964
1965#............................. Calculated Diffractogram
1966
1967data_pd_calc_[pd]
1968    _name                       '_pd_calc_[pd]'
1969    _category                     category_overview
1970    _type                         null
1971
1972    _definition
1973;              This section is used for storing a computed diffractogram trace.
1974               This may be a simulated powder pattern for a material from a
1975               program such as LAZY/PULVERIX or the computed intensities from a
1976               Rietveld refinement.
1977;
1978
1979
1980data_pd_calc_intensity_
1981    loop_ _name                 '_pd_calc_intensity_net'
1982                                '_pd_calc_intensity_total'
1983    _category                    pd_data
1984    _type                        numb
1985    _list                        yes
1986    _enumeration_range           0.0:
1987    _definition
1988;              Intensity values for a computed diffractogram at
1989               each angle setting. Values should be computed at the
1990               same locations as the processed diffractogram, and thus
1991               the numbers of points will be defined by
1992               _pd_proc_number_of_points and point positions may
1993               be defined using _pd_proc_2theta_range_ or
1994               _pd_proc_2theta_corrected.
1995
1996               Use _pd_calc_intensity_net if the computed diffractogram
1997               does not contain background or normalization corrections
1998               and thus is specified on the same scale as the
1999               _pd_proc_intensity_net values.
2000
2001               Use _pd_calc_intensity_total if the computed diffraction
2002               pattern includes background or normalization corrections
2003               (or both) and thus is specified on the same scale as the
2004               observed intensities (_pd_meas_counts_ or _pd_meas_intensity_).
2005
2006               If an observed pattern is included, _pd_calc_intensity_
2007               should be looped with either _pd_proc_intensity_net,
2008               _pd_meas_counts_ or _pd_meas_intensity_.
2009;
2010
2011data_pd_calc_method
2012    _name                      '_pd_calc_method'
2013    _category                    pd_calc
2014    _type                        char
2015    _definition
2016;              A description of the method used for the calculation of
2017               the intensities in _pd_calc_intensity_. If the pattern was
2018               calculated from crystal structure data, the atom coordinates
2019               and other crystallographic information should be included
2020               using the core CIF _atom_site_ and _cell_ data items.
2021;
2022
2023
2024#......................... Peak Table
2025
2026data_pd_peak_[pd]
2027    _name                       '_pd_peak_[pd]'
2028    _category                     category_overview
2029    _type                         null
2030    _definition
2031;              This section contains peak information extracted from the
2032               measured or, if present, the processed diffractogram. Each
2033               peak in this table will have a unique label (see _pd_peak_id).
2034               The reflections and phases associated with each peak will be
2035               specified in other sections (see the _pd_refln_ and
2036               _pd_phase_ sections).
2037
2038               Note that peak positions are customarily determined from the
2039               processed diffractogram and thus corrections for position
2040               and intensity will have been previously applied.
2041;
2042
2043data_pd_peak_2theta_
2044    loop_ _name                  '_pd_peak_2theta_centroid'
2045                                 '_pd_peak_2theta_maximum'
2046    _category                    pd_peak
2047    _type                        numb
2048    _type_conditions             esd
2049    _list                        yes
2050    _list_reference            '_pd_peak_id'
2051    _units                       deg
2052    _units_detail               'degrees'
2053    _enumeration_range           0.0:180.0
2054    _definition
2055;              Position of the centroid and maximum of a peak as a
2056               2\q angle in degrees.
2057;
2058
2059data_pd_peak_d_spacing
2060    _name                      '_pd_peak_d_spacing'
2061    _category                    pd_peak
2062    _type                        numb
2063    _type_conditions             esd
2064    _list                        yes
2065    _list_reference            '_pd_peak_id'
2066    _enumeration_range           0.0:
2067    _units                       A
2068    _units_detail               'angstroms'
2069    _definition
2070;              Peak position as a d-spacing in angstroms.
2071;
2072
2073data_pd_peak_id
2074    _name                      '_pd_peak_id'
2075    _category                    pd_peak
2076    _type                        char
2077    _list                        yes
2078    _list_mandatory              yes
2079    _list_uniqueness           '_pd_peak_id'
2080    _list_link_child           '_pd_refln_peak_id'
2081    _definition
2082;              An arbitrary code is assigned to each peak. Used to link with
2083               _pd_refln_peak_id so that multiple hkl and/or phase
2084               identifications can be assigned to a single peak.
2085               Each peak will have a unique code. In cases
2086               where two peaks are severely overlapped, it may be
2087               desirable to list them as a single peak.
2088
2089               A peak ID must be included for every peak.
2090;
2091
2092data_pd_peak_intensity
2093    _name                      '_pd_peak_intensity'
2094    _category                    pd_peak
2095    _type                        numb
2096    _type_conditions             esd
2097    _list                        yes
2098    _list_reference            '_pd_peak_id'
2099    _enumeration_range           0.0:
2100    _definition
2101;              Integrated area for the peak, with the same scaling as
2102               the _pd_proc_intensity_ values. It is good practice to
2103               include s.u.'s for these values.
2104;
2105
2106data_pd_peak_pk_height
2107    _name                      '_pd_peak_pk_height'
2108    _category                    pd_peak
2109    _type                        numb
2110    _type_conditions             esd
2111    _list                        yes
2112    _list_reference            '_pd_peak_id'
2113    _enumeration_range           0.0:
2114    _definition
2115;              The maximum intensity of the peak, either extrapolated
2116               or the highest observed intensity value. The same
2117               scaling is used for the _pd_proc_intensity_ values.
2118               It is good practice to include s.u.'s for these values.
2119;
2120
2121data_pd_peak_special_details
2122    _name                      '_pd_peak_special_details'
2123    _category                    pd_peak_method
2124    _type                        char
2125    _definition
2126;              Detailed description of any non-routine processing steps
2127               used for peak determination or other comments
2128               related to the peak table that cannot be given elsewhere.
2129;
2130
2131data_pd_peak_wavelength_id
2132    _name                      '_pd_peak_wavelength_id'
2133    _category                    pd_peak
2134    _type                        char
2135    _list                        yes
2136    _list_reference            '_pd_peak_id'
2137    _list_link_parent          '_diffrn_radiation_wavelength_id'
2138    _definition
2139;              Code identifying the wavelength appropriate for this peak
2140               from the wavelengths in the _diffrn_radiation_ list.
2141               (See _diffrn_radiation_wavelength_id.) Most commonly used
2142               to distinguish K\a~1~ peaks from K\a~2~ or to designate
2143               where K\a~1~ and K\a~2~ peaks cannot be resolved. For
2144               complex peak tables with multiple superimposed peaks,
2145               specify wavelengths in the reflection table using
2146               _pd_refln_wavelength_id rather than identifying peaks by
2147               wavelength.
2148;
2149
2150data_pd_peak_width_2theta
2151    _name                      '_pd_peak_width_2theta'
2152    _category                    pd_peak
2153    _type                        numb
2154    _type_conditions             esd
2155    _list                        yes
2156    _list_reference            '_pd_peak_id'
2157    _enumeration_range           0.0:180.0
2158    _units                       deg
2159    _units_detail                degrees
2160    _definition
2161;              Peak width as full-width at half-maximum expressed as
2162               a 2\q value in degrees.
2163;
2164
2165data_pd_peak_width_d_spacing
2166    _name                      '_pd_peak_width_d_spacing'
2167    _category                    pd_peak
2168    _type                        numb
2169    _type_conditions             esd
2170    _list                        yes
2171    _list_reference            '_pd_peak_id'
2172    _enumeration_range           0.0:
2173    _units                       A
2174    _units_detail               'angstroms'
2175    _definition
2176;              Peak width as full-width at half-maximum expressed as
2177               a d-spacing in angstroms.
2178;
2179
2180#............................ Crystalline Phase Assignments
2181
2182data_pd_phase_[pd]
2183    _name                       '_pd_phase_[pd]'
2184    _category                     category_overview
2185    _type                         null
2186
2187    _definition
2188;              This section contains a description of the crystalline phases
2189               contributing to the powder diffraction data set. Note that if
2190               multiple-phase Rietveld or other structural analysis is
2191               performed, the structural results will be placed in different
2192               data blocks, using CIF entries from the core CIF dictionary.
2193
2194               The _pd_phase_block_id entry points to the CIF block with
2195               structural parameters for each crystalline phase. The
2196               _pd_phase_id serves to link to _pd_refln_phase_id, which is
2197               used to label peaks by phase.
2198;
2199
2200data_pd_phase_block_id
2201    _name                      '_pd_phase_block_id'
2202    _category                    pd_phase
2203    _type                        char
2204    _list                        yes
2205    _list_reference            '_pd_phase_id'
2206    _definition
2207;              A block ID code identifying the phase contributing to
2208               the diffraction peak. The data block containing the
2209               crystallographic information for this phase will be
2210               identified with a _pd_block_id code matching the
2211               code in _pd_phase_block_id.
2212;
2213
2214data_pd_phase_id
2215    _name                      '_pd_phase_id'
2216    _category                    pd_phase
2217    _type                        char
2218    _list                        yes
2219    _list_mandatory              yes
2220    _list_link_child           '_pd_refln_phase_id'
2221    _list_uniqueness           '_pd_phase_id'
2222    _definition
2223;              A code for each crystal phase used to link with
2224               _pd_refln_phase_id.
2225;
2226
2227data_pd_phase_mass_%
2228    _name                      '_pd_phase_mass_%'
2229    _category                    pd_phase
2230    _type                        numb
2231    _type_conditions             esd
2232    _list                        yes
2233    _list_reference            '_pd_phase_id'
2234    _enumeration_range           0.0:100.0
2235    _definition
2236;              Per cent composition of the specified crystal phase
2237               expressed as the total mass of the component
2238               with respect to the total mass of the specimen.
2239;
2240
2241data_pd_phase_name
2242    _name                      '_pd_phase_name'
2243    _category                    pd_phase
2244    _type                        char
2245    _list                        both
2246    _list_reference            '_pd_phase_id'
2247    _definition
2248;              The name of the crystal phase identified by _pd_phase_id.
2249               It may be designated as unknown or by a structure type etc.
2250;
2251
2252#............................ Peak Reflection Identification
2253
2254data_pd_refln_[pd]
2255    _name                       '_pd_refln_[pd]'
2256    _category                     category_overview
2257    _type                         null
2258    _definition
2259;              This section provides a mechanism to identify each peak in the
2260               peak-table section (_pd_peak_) with the phase(s) (_pd_phase_id)
2261               and the reflection indices (_refln_index_) associated with the
2262               peak.  There are no restrictions on the number of phases or
2263               reflections associated with an observed peak. Reflections may
2264               also be included that are not observed; use '.' for the
2265               _pd_refln_peak_id.
2266;
2267
2268data_pd_refln_peak_id
2269    _name                      '_pd_refln_peak_id'
2270    _category                    refln
2271    _type                        char
2272    _list                        yes
2273    loop_ _list_reference      '_refln_index_h'
2274                               '_refln_index_k'
2275                               '_refln_index_l'
2276    _list_link_parent          '_pd_peak_id'
2277    _definition
2278;              Code which identifies the powder diffraction peak that
2279               contains the current reflection. This code must match a
2280               _pd_peak_id code.
2281;
2282
2283data_pd_refln_phase_id
2284    _name                      '_pd_refln_phase_id'
2285    _category                    refln
2286    _type                        char
2287    _list                        yes
2288    loop_ _list_reference      '_refln_index_h'
2289                               '_refln_index_k'
2290                               '_refln_index_l'
2291    _list_link_parent          '_pd_phase_id'
2292    _definition
2293;              Code which identifies the crystal phase associated with this
2294               reflection. This code must match a _pd_phase_id code.
2295;
2296
2297data_pd_refln_wavelength_id
2298    _name                      '_pd_refln_wavelength_id'
2299    _category                    refln
2300    _type                        char
2301    _list                        yes
2302    loop_ _list_reference      '_refln_index_h'
2303                               '_refln_index_k'
2304                               '_refln_index_l'
2305    _list_link_parent          '_diffrn_radiation_wavelength_id'
2306    _definition
2307;              Code which identifies the wavelength associated with the
2308               reflection and the peak pointed to by _pd_refln_peak_id.
2309               This code must match a _diffrn_radiation_wavelength_id code.
2310;
2311
2312#............................. Sample Preparation Information
2313
2314data_pd_prep_[pd]
2315    _name                       '_pd_prep_[pd]'
2316    _category                     category_overview
2317    _type                         null
2318    _definition
2319;              This section contains descriptive information about how the
2320               sample was prepared.
2321;
2322
2323data_pd_prep_conditions
2324    _name                      '_pd_prep_conditions'
2325    _category                    pd_prep
2326    _type                        char
2327    _definition
2328;              A description of how the material was prepared
2329               (reaction conditions etc.)
2330;
2331
2332data_pd_prep_cool_rate
2333    _name                      '_pd_prep_cool_rate'
2334    _category                    pd_prep
2335    _type                        numb
2336    _type_conditions             esd
2337    _enumeration_range           0.0:
2338    _units                       Kmin^-1^
2339    _units_detail               'kelvins/minute'
2340    _definition
2341;              Cooling rate in kelvins per minute for samples prepared
2342               at high temperatures. If the cooling rate is not linear
2343               or is unknown (e.g. quenched samples), it should be
2344               described in _pd_prep_conditions instead.
2345;
2346
2347data_pd_prep_pressure
2348    _name                      '_pd_prep_pressure'
2349    _category                    pd_prep
2350    _type                        numb
2351    _type_conditions             esd
2352    _enumeration_range           0.0:
2353    _units                       kPa
2354    _units_detail               'kilopascals'
2355    _definition
2356;              Preparation pressure of the sample in kilopascals. This
2357               is particularly important for materials which are metastable
2358               at the measurement pressure, _diffrn_ambient_pressure.
2359;
2360
2361data_pd_prep_temperature
2362    _name                      '_pd_prep_temperature'
2363    _category                    pd_prep
2364    _type                        numb
2365    _type_conditions             esd
2366    _enumeration_range           0.0:
2367    _units                       K
2368    _units_detail               'kelvin'
2369    _definition
2370;              Preparation temperature of the sample in kelvins. This is
2371               particularly important for materials which are metastable
2372               at the measurement temperature, _diffrn_ambient_temperature.
2373;
2374
2375#............................. Characterisation Information
2376
2377data_pd_char_[pd]
2378    _name                       '_pd_char_[pd]'
2379    _category                     category_overview
2380    _type                         null
2381    _definition
2382;   This section contains experimental (non-diffraction) information
2383    relevant to the chemical and physical nature of the material.
2384;
2385
2386data_pd_char_atten_coef_mu_
2387    loop_ _name                '_pd_char_atten_coef_mu_obs'
2388                               '_pd_char_atten_coef_mu_calc'
2389    _category                    pd_char
2390    _type                        numb
2391    _enumeration_range           0.0:
2392    _units                       mm^-1^
2393    _units_detail                'reciprocal millimetres'
2394    _definition
2395;              The observed and calculated linear attenuation coefficient,
2396               \m, in units of inverse millimetres. Note that this quantity
2397               is sometimes referred to as the mass absorption coefficient;
2398               however, this term accounts for other potentially significant
2399               losses of incident radiation, for example incoherent
2400               scattering of neutrons.
2401
2402               The calculated \m will be obtained from the atomic content of
2403               the cell, the average density (allowing for specimen packing)
2404               and the radiation wavelength. The observed \m will be
2405               determined by a transmission measurement.
2406               Note that _pd_char_atten_coef_mu_calc will differ from
2407               _exptl_absorpt_coefficient_mu if the packing density is
2408               not unity.
2409;
2410
2411data_pd_char_colour
2412    _name                      '_pd_char_colour'
2413    _category                    pd_char
2414    _type                        char
2415    loop_ _example               dark_green
2416                                 orange_red
2417                                 brownish_red
2418                                 yellow_metallic
2419    _definition
2420;              The colour of the material used for the measurement.
2421               To facilitate more standardized use of names, the
2422               following guidelines for colour naming developed by
2423               Peter Bayliss for the International Centre for
2424               Diffraction Data (ICDD) should be followed. Note that
2425               combinations of descriptors are separated by an
2426               underscore.
2427
2428               Allowed colours are:
2429                 colourless, white, black, gray, brown, red, pink,
2430                 orange, yellow, green, blue, violet.
2431
2432               Colours may be modified using prefixes of:
2433                 light, dark, whitish, blackish, grayish, brownish,
2434                 reddish, pinkish, orangish, yellowish, greenish, bluish.
2435
2436               Intermediate hues may be indicated with two colours:
2437               e.g. blue_green or bluish_green.
2438
2439               For metallic materials, the term metallic may be added:
2440               e.g. reddish_orange_metallic for copper.
2441
2442               The ICDD standard allows commas to be used for minerals
2443               that occur with ranges of colours; however this usage is
2444               not appropriate for the description of a single sample.
2445;
2446
2447data_pd_char_particle_morphology
2448    _name                      '_pd_char_particle_morphology'
2449    _category                    pd_char
2450    _type                        char
2451    _definition
2452;              A description of the sample morphology and estimates for
2453               particle sizes (before grinding/sieving, if noted by
2454               _pd_spec_preparation). Include the method used for
2455               these estimates (SEM, visual estimate etc.).
2456;
2457
2458data_pd_char_special_details
2459    _name                      '_pd_char_special_details'
2460    _category                    pd_char
2461    _type                        char
2462    _definition
2463;              Additional characterization information relevant to the sample
2464               or documentation of non-routine processing steps used
2465               for characterization.
2466;
2467
2468#............................. Data Tabulation and Book-keeping Across Tables
2469
2470data_pd_data_[pd]
2471    _name                       '_pd_data_[pd]'
2472    _category                     category_overview
2473    _type                         null
2474    loop_ _example
2475          _example_detail
2476# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2477;
2478    loop_
2479      _pd_data_point_id
2480      _pd_meas_intensity_total
2481      _pd_proc_ls_weight
2482      _pd_proc_intensity_bkg_calc
2483      _pd_calc_intensity_total
2484    1    240(15)       0.00417     214.5   214.5
2485    2    219(15)       0.00457     214.3   214.2
2486    3    206(14)       0.00485     214.0   214.0
2487    4    212(15)       0.00472     213.8   213.7
2488    5    190(14)       0.00526     213.5   213.5
2489    6    203(14)       0.00493     213.2   213.2
2490     # - - - - data truncated for brevity - - - -
2491;
2492;   Example 1 - data set collected for a two-phase sample (Al~2~O~3~/Si)
2493                by B. H. Toby, '1997-01-29T16:37|POWSET_01|B.Toby|..NIST-D5000'.
2494;
2495# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2496;
2497     loop_
2498      _pd_meas_point_id
2499      _pd_meas_intensity_total
2500    1  240(15) 2  219(15) 3  206(14) 4  212(15) 5  190(14) 6  203(14)
2501
2502     loop_
2503      _pd_proc_point_id
2504      _pd_proc_ls_weight
2505      _pd_proc_intensity_bkg_calc
2506    1  0.00417  214.5      2  0.00457  214.3
2507    3  0.00485  214.0      4  0.00472  213.8
2508    5  0.00526  213.5      6  0.00493  213.2
2509
2510     loop_
2511      _pd_calc_point_id
2512      _pd_calc_intensity_total
2513    1   214.5 2   214.2 3   214.0 4   213.7 5   213.5 6   213.2
2514
2515;
2516;   Example 2 - the data of Example 1 split into three separate tables.
2517;
2518# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2519;
2520   loop_
2521     _pd_meas_point_id
2522     _pd_meas_2theta_scan
2523     _pd_meas_intensity_total
2524            1  21.0   24
2525            2  21.2   32
2526            3  21.4   67
2527            4  21.6   98
2528
2529   loop_
2530     _pd_calc_point_id
2531     _pd_proc_2theta_corrected
2532     _pd_calc_intensity_total
2533            1   21.0  26
2534            1a  21.3  56
2535            4   21.6  76
2536            4a  21.9  90
2537
2538;
2539;   Example 3 - hypothetical example where the measured and calculated
2540                points are not in one-to-one correspondence.
2541;
2542# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2543    _definition
2544;              The PD_DATA category contains raw, processed and calculated
2545               data points in a diffraction data set. In many cases, it is
2546               convenient to tabulate calculated values against the
2547               raw and processed measurements, and so the various
2548               _pd_meas_, _pd_proc_ and _pd_calc_ data items belonging
2549               to this category may be looped together. In some instances,
2550               however, it makes more sense to maintain separate tables of
2551               the data contributing to the measured and processed
2552               diffractograms (for example, a profile may be calculated
2553               at 2theta values different from those of the measured
2554               data points). To facilitate the identification of equivalent
2555               points in these separate tables, separate identifiers are
2556               defined.
2557;
2558
2559data_pd_calc_point_id
2560    _name                      '_pd_calc_point_id'
2561    _category                    pd_data
2562    _type                        char
2563    _related_item              '_pd_data_point_id'
2564    _related_function            alternate
2565    _definition
2566;              Arbitrary label identifying a calculated data point. Used to
2567               identify a specific entry in a list of values forming the
2568               calculated diffractogram. The role of this identifier may
2569               be adopted by _pd_data_point_id if measured, processed and
2570               calculated intensity values are combined in a single list.
2571;
2572
2573data_pd_data_point_id
2574    _name                      '_pd_data_point_id'
2575    _category                    pd_data
2576    _type                        char
2577    _definition
2578;              Arbitrary label identifying an entry in the table of
2579               diffractogram intensity values.
2580;
2581
2582data_pd_meas_point_id
2583    _name                      '_pd_meas_point_id'
2584    _category                    pd_data
2585    _type                        char
2586    _related_item              '_pd_data_point_id'
2587    _related_function            alternate
2588    _definition
2589;              Arbitrary label identifying a measured data point. Used to
2590               identify a specific entry in a list of measured intensities.
2591               The role of this identifier may be adopted by
2592               _pd_data_point_id if measured, processed and calculated
2593               intensity values are combined in a single list.
2594;
2595
2596data_pd_proc_point_id
2597    _name                      '_pd_proc_point_id'
2598    _category                    pd_data
2599    _type                        char
2600    loop_ _related_item
2601          _related_function
2602                               '_pd_data_point_id'            alternate
2603                               '_pd_meas_point_id'            alternate
2604    _definition
2605;              Arbitrary label identifying a processed data point. Used to
2606               identify a specific entry in a list of processed intensities.
2607               The role of this identifier may be adopted by
2608               _pd_data_point_id if measured, processed and calculated
2609               intensity values are combined in a single list, or by
2610               _pd_meas_point_id if measured and processed lists are
2611               combined.
2612;
2613
2614#eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof-eof
Note: See TracBrowser for help on using the repository browser.