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This guide is a quick introduction to the DIFFRAC.EVA software (version 5.1) and how to use the program to solve crystalline phase identification. For detailed information and an in-depth guide refer to DIFFRAC.EVALUATION User Guide & Tutorial available in hard copy in the X-Ray Lab or online in Cumulus at XRD Books and Reference Material.
For former version of DIFFRAC.EVA software, refer to hard copy available in the X-Ray Lab.
Opening a Diffractogram in DIFFRAC.EVA
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Select the desired search parameters (see suggestions below and Figures 6, 7 and 8). Once the desired parameters are selected, click Rebuild to rebuild the database for your selections. After the database is rebuilt, click back onto Candidate List and click Match.
Figure 4. A. Search/Match, B. Auto Views Panel, C. Search/Match dialog box
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In the Databases Tab, select the DB Filter. Click on the "three dots" button 
(Figure 6A). The Database Filter window opens (Figure 6). The default name is 'Database Filter #1', and the database used is "PDF-2 2001". The Search/Match can be enhanced using database filters such as the following (Figure 6):
–Quality Marks: Degrees of pattern quality assigned by ICDD. Recommended: *, Calculated, Indexed (a).
–Status: Recommended: Primary (b).
–Colors: Select the color of the mineral to be searched.
–Sources: Database section: select both ICDD Database (experimental) and ICSD Database (ICSD-FIZ) (c).
–Subfiles: Select the group of patterns to be searched, for example, inorganics, zeolites, minerals, etc. (d).
–Element # in Formula: Choose the minimum/maximum number of elements considered in the formula (default values are min=1 and max=24).
–Density: Enter a minimum/maximum density for the mineral being searched (default values are min=1 and max=80).
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Figure 7. Chemical Filter.
Candidate List Tab
Once the desired parameters are selected, click Rebuild to rebuild the database for your selections (Figure 6B). After the database is rebuilt, click back onto Match Lists (Figure 8). In the drop-down menu, select the list of clay minerals and common minerals and click OK (Figure 8A). Then, click Match (Figure 8B).
Close the window.
Figure 8. Match Lists
In the Auto Views panel, the list of candidates appears (Figure 9). Expand the table to see important information on the candidate (Figure
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9), including
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:
–Index # 
: Rank number of the given pattern during the Search run
–Match: Number of reference pattern lines matching the unknown. The Match Column gives: on the left (green bar) the number of reference pattern lines matching the unknown in the displayed range, on the right (orange bar) the number of reference pattern lines not matching the unknown.
–FOM: Figure of Merit –
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the higher this number, the better the match. Patterns are sorted by decreasing FOM. The FOM is represented by a blue bar proportional to its value.
Check the tick box (green square in Figure 8) to add selected peaks. To delete selected peaks, right-click on the selection and choose 'Delete'.
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Figure 8. Candidate Search List Tab .in the Auto Views Panel
Residual Scan –
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Searching the minor phases
Minor phases are often sometimes difficult to identify because the patterns of the major peaks are higher on have a better position in the list. Using the Residue tool will exclude the already matched patterns and increase the weight of the minor phases.
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In Search/Match (scan) screen, choose the Selected Candidates tab.
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Select the pattern you wish to exclude in your next search.
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Select the Residue tool.
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Adjust the width of the zone to exclude around the pattern peaks.
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Click Apply.
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Click back onto Candidate List Tab and click Match.
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The candidates for the residual scan are listed in Candidate List
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Click 
(Residual Scan) or right-click anywhere on the Graphical 1D View and then choose Residual Scan > Residue (all scans) (Figure 9). Select the area you want to exclude. The area will be displayed in red. To restore the excluded part, click the Undo arrow 
or right-click and choose Residual Scan > Restore (all scans).
Check the tick box (green square in Figure 9) to add selected peaks. To delete selected peaks, right-click on the selection and choose 'Delete'.
Figure 9. Residual Scan
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Select the Scissors tool from the View Window toolbar.
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Cut the peaks that you wish to exclude from the Search/Match.
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Under Search/Match (scan) box,in the Candidate List tab, select Match.
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The program will search the peaks left uncut.
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Peak Search
Peak Search detects peaks automatically and is useful for phases not identified with Search/Match or to export the pattern to another program.
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