Peak Editing in the Diffraction Pattern

You can edit the peaks directly in the diffraction pattern using the mouse. Normally, this works best in combination with zooming and tracking/panning.

Note: If the mouse cursor does not change as expected in any of the following operations, you need to give the input focus to the diffraction pattern first, e.g. by clicking on it!

Add peak: If you would like to add a peak, please press the <Ctrl> button (<Cmd> on a Mac) first; the mouse cursor will change to . Keep the button pressed, move the mouse pointer to the corresponding 2theta position, and click the right mouse button. A peak will be inserted at the corresponding position. Once you have finished adding peaks, you can release the <Ctrl> keyboard button.
Depending on the (de-)activation of the profile fitting settings (2theta, intensity and/or FWHM), the 2theta, intensity and/or FWHM value(s) of the new peak will be instantly optimized by automatic profile fitting right after you have clicked the mouse button. If all three profile fitting options (2theta, intensity and FWHM) are active, it is sufficient to (right-)click somewhere in the peak area below the profile curve in order to add the peak. If the calculated profile is currently displayed, the new peak data will be included in the profile and Rp-factor calculation automatically.
If there are no profile data present, the top of the peak (i.e. the peak intensity) will be taken from the position of the mouse cursor. The FWHM of the peak will be set to the corresponding default value.
Please note: After adding the strongest peak you may want to run the Scale relative intensities command from the "Peaks" menu, in order to adjust the maximum relative peak intensity to a value of 1000.0 .

Mark peak(s): There are several options to mark one or more peak(s):

Marked peaks are indicated by a small triangle displayed at the top of the peaks, and of course the corresponding lines in the peak list are inverted.

Edit peak position: If you would like to edit a peak position (i.e. shift a peak on the 2theta axis), please move the mouse cursor close to the peak position (below the peak top), so that the mouse cursor changes to . Afterwards, press the right mouse button and move the mouse to the position inside the current viewing region where you would like to place the peak. Finally, release the mouse button. If the calculated profile and the Rp-factor are currently displayed, they will be updated with regard to the new peak position.

Edit peak position and/or intensity: You can also modify both peak position and intensity at the same time: Please move the mouse cursor close to the top of the corresponding peak until the mouse cursor changes to , then press the right mouse button and move the mouse to the intensity/2theta position where you would like to place the peak. Finally, release the right mouse button. If the calculated profile and the Rp-factor are currently displayed, they will be updated with regard to the new peak position.

Edit peak FWHM: You can modify the FWHM (Full Width at Half Maximum) of marked peaks using the mouse: Mark one (or more) peaks as described above, then move the mouse over one of the marked peaks until the mouse cursor changes to , and finally turn the mouse wheel in order to modify the FWHM of the marked peak(s).

Invert peak mark(s): If you would like to mark all but a few peaks, you should use the "invert peak marks" facility: First, mark the few peaks you do not want to mark (see above), then press the right mouse button within the diffraction pattern (which will open the context menu), and select "Invert selection" from the menu.

Delete peak(s): In order to delete one or more peaks, you first have to mark the corresponding peaks in the diffraction pattern (see above). Once you have marked one or more peaks, there are several options to delete them:

If the calculated profile and the Rp-factor are currently displayed, they will be updated with regard to the remaining peaks.

Deactivate peak(s): You can deactivate individual peaks of the unknown sample's pattern so that they are not taken into account during the figure-of-merit calculation. This is e.g. useful if you are not sure about a certain peak and would like to check what would be the result of the search-match without this peak.

Mind the difference to the exclusion of whole pattern areas! In case of the latter, the effect is the same as if the corresponding area would not have been recorded at all (or cropped before the analysis): There is no information present in this pattern area, so it does not matter if reference entries have peaks in this area or not.
If on the other hand peaks are deactivated, these peaks are neglected, however, the corresponding 2theta range is still considered during the figure-of-merit calculation! The result is the same as if the deactivated peaks would not be there at all. Peaks of reference entries are still compared to the corresponding 2theta range of the experimental pattern.

In order to deactivate one or more peaks, you first have to mark them (see above). Afterwards, please press the right mouse button within the diffracton pattern, and select "Deactivate" from the context menu (or use the corresponding command from the "Peaks" menu). The candidate list will immediately reflect the change in the FoM-values of the entries. However, you should perhaps perform a complete new search-match operation in order to check if there are new matching entries! Please note that deactivated peaks are displayed in light grey in the diffraction pattern.

Activate peak(s): You can reactivate individual peaks of the unknown sample's pattern you have deactivated earlier. Please mark the corresponding peaks (see above), then press the right mouse button within the diffracton pattern, and select "Activate" from the context menu (or use the corresponding command from the "Peaks" menu).

See also: