Changeset 1752


Ignore:
Timestamp:
Mar 21, 2015 9:55:21 AM (7 years ago)
Author:
vondreele
Message:

add missing figs.

Location:
Tutorials/SeqRefine
Files:
17 added
2 edited

Legend:

Unmodified
Added
Removed
  • Tutorials/SeqRefine/SequentialTutorial.htm

    r1745 r1752  
    2323  <o:Author>B Toby</o:Author>
    2424  <o:LastAuthor>Von Dreele</o:LastAuthor>
    25   <o:Revision>3</o:Revision>
    26   <o:TotalTime>395</o:TotalTime>
    27   <o:Created>2014-07-22T20:46:00Z</o:Created>
    28   <o:LastSaved>2015-03-20T13:46:00Z</o:LastSaved>
     25  <o:Revision>2</o:Revision>
     26  <o:TotalTime>396</o:TotalTime>
     27  <o:Created>2015-03-21T14:51:00Z</o:Created>
     28  <o:LastSaved>2015-03-21T14:51:00Z</o:LastSaved>
    2929  <o:Pages>1</o:Pages>
    30   <o:Words>3774</o:Words>
    31   <o:Characters>21517</o:Characters>
     30  <o:Words>3769</o:Words>
     31  <o:Characters>21484</o:Characters>
    3232  <o:Company>Argonne National Laboratory</o:Company>
    3333  <o:Lines>179</o:Lines>
    3434  <o:Paragraphs>50</o:Paragraphs>
    35   <o:CharactersWithSpaces>25241</o:CharactersWithSpaces>
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    3636  <o:Version>15.00</o:Version>
    3737 </o:DocumentProperties>
     
    4040 </o:OfficeDocumentSettings>
    4141</xml><![endif]-->
    42 <link rel=dataStoreItem href="SequentialTutorial_files/item0110.xml"
    43 target="SequentialTutorial_files/props111.xml">
     42<link rel=dataStoreItem href="SequentialTutorial_files/item0111.xml"
     43target="SequentialTutorial_files/props112.xml">
    4444<link rel=themeData href="SequentialTutorial_files/themedata.thmx">
    4545<link rel=colorSchemeMapping
     
    14171417<p class=MsoNormal><o:p>&nbsp;</o:p></p>
    14181418
    1419 <p class=MsoNormal>This example assumes that one is already familiar with use of
    1420 GSAS-II for simple refinements.</p>
     1419<p class=MsoNormal>This example assumes that one is already familiar with use
     1420of GSAS-II for simple refinements.</p>
    14211421
    14221422<h1>Step 1: Fit a single temperature. </h1>
     
    17331733the <b style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    17341734mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>Phase</span></b>
    1735 entry to “open” the tree item). We also want to refine the phase fraction for
    1736 this phase, so <span style='mso-bidi-font-weight:bold'>select the<b> </b></span><b><span
     1735entry to “open” the tree item). We also want to refine the phase fraction for this
     1736phase, so <span style='mso-bidi-font-weight:bold'>select the<b> </b></span><b><span
    17371737style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    17381738mso-hansi-theme-font:major-latin'>Data</span> </b><span style='mso-bidi-font-weight:
     
    18421842style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    18431843mso-hansi-theme-font:major-latin'>4.5</span>.</b> <b style='mso-bidi-font-weight:
    1844 normal'><i style='mso-bidi-font-style:normal'><u>Important</u></i></b>: you
    1845 will have to select the data box (it will turn blue) and then enter the number
    1846 (<b style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
     1844normal'><i style='mso-bidi-font-style:normal'><u>Important</u></i></b>: you will
     1845have to select the data box (it will turn blue) and then enter the number (<b
     1846style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    18471847mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>4.5</span></b>)
    18481848and then click on some other box in the window so that the change registers. </p>
     
    19341934"Calibri",sans-serif;mso-ascii-theme-font:major-latin;mso-hansi-theme-font:
    19351935major-latin'>PWDR OH_00.fxye Bank 1</span> </b><span style='mso-bidi-font-weight:
    1936 bold'>entry</span> shows the “Rietveld plot” and zooming in on different regions
    1937 of the pattern provides insight on how the fit could be improved. You can alter
    1938 the view to show the square root of the intensity (use the ‘<b
     1936bold'>entry</span> shows the “Rietveld plot” and zooming in on different
     1937regions of the pattern provides insight on how the fit could be improved. You
     1938can alter the view to show the square root of the intensity (use the ‘<b
    19391939style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    19401940mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>S</span></b>’
     
    20302030<p class=MsoListParagraphCxSpMiddle>Close examination of the pattern shows that
    20312031the peak widths are still not as well fit as desired. Since strain broadening
    2032 seems more significant that sample broadening, we could use an anisotropic strain
    2033 model. Rather than choosing the relatively complex generalized model, we can
    2034 introduce only two terms with the uniaxial model.<span
     2032seems more significant that sample broadening, we could use an anisotropic
     2033strain model. Rather than choosing the relatively complex generalized model, we
     2034can introduce only two terms with the uniaxial model.<span
    20352035style='mso-spacerun:yes'>  </span>Trial and error will show that the 010
    20362036direction works best. Click on the first phase (<b style='mso-bidi-font-weight:
     
    20822082
    20832083<p class=MsoNormal>There is one significant difference between fitting a
    2084 sequence of datasets versus fitting a single data set. Rather than fitting lattice
    2085 constants (for which there will be only one set for each phase in the entire
    2086 refinement), we will use the Hydrostatic/Elastic strain terms (parameters
    2087 &lt;p&gt;:&lt;h&gt;:Dxx) to treat the change in lattice parameters. These items
    2088 describe the change in lattice parameters and appear in the Phase Data tab,
    2089 where there is a set for each histogram assigned to the phase. We will make a
    2090 switch to use this for the current dataset, in preparation for the sequential
    2091 refinement with all datasets. </p>
     2084sequence of datasets versus fitting a single data set. Rather than fitting
     2085lattice constants (for which there will be only one set for each phase in the
     2086entire refinement), we will use the Hydrostatic/Elastic strain terms
     2087(parameters &lt;p&gt;:&lt;h&gt;:Dxx) to treat the change in lattice parameters.
     2088These items describe the change in lattice parameters and appear in the Phase
     2089Data tab, where there is a set for each histogram assigned to the phase. We
     2090will make a switch to use this for the current dataset, in preparation for the
     2091sequential refinement with all datasets. </p>
    20922092
    20932093<p class=MsoNormal><o:p>&nbsp;</o:p></p>
     
    20992099(that might eliminate our impurity CuO phase) or make peaks quite a bit broader
    21002100than appropriate, these changes are improbable and could result in a model that
    2101 is less correct than the starting point but still be a local LS minimum. In such
    2102 cases the best-fit model may never be found. Accordingly, we will turn off
     2101is less correct than the starting point but still be a local LS minimum. In
     2102such cases the best-fit model may never be found. Accordingly, we will turn off
    21032103refinement of all parameters except those that determine peak positions (the
    21042104Dxx terms) and the overall scale factor. We might include the background terms
     
    21912191style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    21922192mso-hansi-theme-font:major-latin'>D13</span></b> term (which corresponds to the
    2193 CuO &#946;* angle), but we do not expect this to change much and expect the refinement
    2194 to be relatively insensitive to this, due to the small number of CuO peaks that
    2195 are in the pattern.)</p>
     2193CuO &#946;* angle), but we do not expect this to change much and expect the
     2194refinement to be relatively insensitive to this, due to the small number of CuO
     2195peaks that are in the pattern.)</p>
    21962196
    21972197<p class=MsoListParagraphCxSpMiddle><o:p>&nbsp;</o:p></p>
     
    23682368style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    23692369mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>K</span></b>”
    2370 icon from the list at the bottom of plot, between the “floppy disk” and “question
    2371 mark” icons and then select “<b style='mso-bidi-font-weight:normal'><span
     2370icon from the list at the bottom of plot, between the “floppy disk” and
     2371“question mark” icons and then select “<b style='mso-bidi-font-weight:normal'><span
    23722372style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    23732373mso-hansi-theme-font:major-latin'>m: toggle multidata plot</span></b>” from the
     
    25872587<p class=MsoNormal><o:p>&nbsp;</o:p></p>
    25882588
    2589 <p class=MsoNormal>At this point we determine which histograms will be used in the
    2590 fit and set that the resulting parameters from the results of each refinement
    2591 will be used for the subsequent refinements.</p>
     2589<p class=MsoNormal>At this point we determine which histograms will be used in
     2590the fit and set that the resulting parameters from the results of each
     2591refinement will be used for the subsequent refinements.</p>
    25922592
    25932593<p class=MsoNormal><o:p>&nbsp;</o:p></p>
     
    26272627
    26282628<p class=MsoListParagraphCxSpMiddle>This opens a window where all histograms
    2629 can be selected (it would be equally valid to skip the first histogram, since
    2630 that has already been fully fit). <span style='mso-bidi-font-weight:bold'>Press<b>
    2631 </b></span><b><span style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:
    2632 major-latin;mso-hansi-theme-font:major-latin'>OK</span></b> and note that the <b
     2629can be selected (it would be equally valid to skip the first histogram, since that
     2630has already been fully fit). <span style='mso-bidi-font-weight:bold'>Press<b> </b></span><b><span
     2631style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
     2632mso-hansi-theme-font:major-latin'>OK</span></b> and note that the <b
    26332633style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    26342634mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>Controls</span></b>
     
    28532853style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
    28542854mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>Sequential
    2855 Results</span></b> item in the data tree is automatically selected, which displays
    2856 a summary of the refinement results as a large table. </p>
     2855Results</span></b> item in the data tree is automatically selected, which
     2856displays a summary of the refinement results as a large table. </p>
    28572857
    28582858<p class=MsoListParagraphCxSpMiddle><o:p>&nbsp;</o:p></p>
     
    28732873parameters, such as strain or background or even atomic coordinates (which have
    28742874not yet been fit). The &#916;&#967;<sup>2</sup> value in the third column shows
    2875 the percent improvement in &#967;<sup>2</sup> seen in the last cycle of
    2876 refinement. (If this changes from 4.1 to 4.0, then the value will be
    2877 100*(4.1-4.0)/4.0, or 2.5). Since the convergence criterion in the controls is
    2878 0.0001 (or 0.01%) we can see that only one refinement failed to converge.
    2879 However, these shifts are still quite small, so that there is no reason to
    2880 provide further cycles of refinement without adding new variable parameters. </p>
     2875the percent improvement in &#967;<sup>2</sup> seen in the last cycle of refinement.
     2876(If this changes from 4.1 to 4.0, then the value will be 100*(4.1-4.0)/4.0, or
     28772.5). Since the convergence criterion in the controls is 0.0001 (or 0.01%) we
     2878can see that only one refinement failed to converge. However, these shifts are
     2879still quite small, so that there is no reason to provide further cycles of
     2880refinement without adding new variable parameters. </p>
    28812881
    28822882<p class=MsoListParagraphCxSpMiddle><o:p>&nbsp;</o:p></p>
     
    29312931style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    29322932mso-hansi-theme-font:major-latin'>s</span></b><span style='mso-bidi-font-weight:
    2933 bold'>” key</span> brings up a menu where the x-axis can be selected as
    2934 temperature. If the plot fails to update, click on another column and then
    2935 return to the original column. </p>
     2933bold'>” key</span> brings up a menu where the x-axis can be selected as temperature.
     2934If the plot fails to update, click on another column and then return to the
     2935original column. </p>
    29362936
    29372937<p class=MsoListParagraphCxSpMiddle><o:p>&nbsp;</o:p></p>
     
    31923192mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>1:0:Scale</span></b>)
    31933193pertains only to the first histogram. Note that a constraint is ignored if none
    3194 of the variables in it are included in the refinement, so this constraint only
    3195 affects the first histogram, giving rise to the error above. We could set up a
     3194of the variables in it are included in the refinement, so this constraint only affects
     3195the first histogram, giving rise to the error above. We could set up a
    31963196constraint for each histogram that has been added, but this would be rather
    31973197tedious to set up. The alternate is to set up a constraint where a wildcard (<span
     
    32823282Three new columns appear at the end of the table for <b style='mso-bidi-font-weight:
    32833283normal'><span style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:
    3284 major-latin;mso-hansi-theme-font:major-latin'>::constr0</span></b> (generated by
    3285 the constraint) and the initial variables, <b style='mso-bidi-font-weight:normal'><span
    3286 style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:major-latin;
    3287 mso-hansi-theme-font:major-latin'>0:*:Scale</span></b> and <b style='mso-bidi-font-weight:
     3284major-latin;mso-hansi-theme-font:major-latin'>::constr0</span></b> (generated
     3285by the constraint) and the initial variables, <b style='mso-bidi-font-weight:
    32883286normal'><span style='font-family:"Calibri",sans-serif;mso-ascii-theme-font:
    3289 major-latin;mso-hansi-theme-font:major-latin'>1:*:Scale</span></b>. Changes to
    3290 the R<sub>wp</sub> values are quite small, even though the value for the minor
    3291 phase changes significantly. This indicates that the refinement is relatively
    3292 insensitive to these values. </p>
     3287major-latin;mso-hansi-theme-font:major-latin'>0:*:Scale</span></b> and <b
     3288style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
     3289mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>1:*:Scale</span></b>.
     3290Changes to the R<sub>wp</sub> values are quite small, even though the value for
     3291the minor phase changes significantly. This indicates that the refinement is
     3292relatively insensitive to these values. </p>
    32933293
    32943294<p class=MsoListParagraphCxSpMiddle><o:p>&nbsp;</o:p></p>
     
    33663366
    33673367<p>This completes the sequential refinement tutorial, although many more things
    3368 could be attempted to further improve the refinement quality. In the <a
    3369 href="ParametricFitting.htm">Parametric Fitting and Pseudo Variables for
    3370 Sequential Fits</a> tutorial, functions of fitted parameters are computed and
    3371 plotted and results are fitted to equations of state.</p>
     3368could be attempted to further improve the refinement quality. In the <b
     3369style='mso-bidi-font-weight:normal'><span style='font-family:"Calibri",sans-serif;
     3370mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin'>Parametric
     3371Fitting and Pseudo Variables for Sequential Fits</span></b> tutorial, functions
     3372of fitted parameters are computed and plotted and results are fitted to
     3373equations of state.</p>
    33723374
    33733375</div>
  • Tutorials/SeqRefine/SequentialTutorial_files/filelist.xml

    r1745 r1752  
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    4  <o:File HRef="props111.xml"/>
     3 <o:File HRef="item0111.xml"/>
     4 <o:File HRef="props112.xml"/>
    55 <o:File HRef="themedata.thmx"/>
    66 <o:File HRef="colorschememapping.xml"/>
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