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cif_pd.dic @ 938

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

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source: gsas/all/data/cif_pd.dic @ 938

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