Peak Searching Sensitivity Adjustment
If you have the impression that a peak searching calculation (either performed directly or implicitly during profile fitting) yielded too many or too few peaks, you should vary the peak searching sensitivity, or, in other words, the tolerance that is applied in the decision if a "hump" in the raw diffraction data results in a peak being added to the peak list or not.
The following commands are available to modify the current peak search sensitivity:
- Increase sensitivity: select command from the submenu "Pattern/Peak Searching" or press "F2" button. More peaks will be detected (added to the peak list) if available.
- Reduce sensitivity: select command from the submenu "Pattern/Peak Searching" or press "F3" button. Some peaks will be removed / fewer peaks will be detected.
- Optimize sensitivity: You can let Match! search for the optimum peak search sensitivity on its own. In order to do so, select command from the submenu "Pattern/Peak Searching" or press "F4" button. Match! minimizes the Rp-factor (agreement between calculated and experimental diffraction pattern) by varying the peak search sensitivity parameter.
- The peaks in the diffraction pattern as well as the peak list, the calculated profile (including Rp-factor), and the FoM values in the candidate list are instantly updated when you modify the peak search sensitivity. As a result, you have an instant visual feedback which allows you to easily adjust the sensitivity according to your requirements.
- Although the FoM-values of the candidate list entries are instantly updated using the new peak data, it is generally recommended to perform a new search-match in order to check if new entries have entered the candidate list.
- The optimization of the peak search sensitivity is only available if a peak search using the normal or the profile fitting method has been performed previously.
- If the peaks have been searched using the profile fitting method, the optimization of the sensitivity parameter will not carry out a new profile fitting calculation. However, you might want to execute this command manually after the optimization in order to obtain more accurate parameters, taking into account any peaks which have been added or removed during the optimization.