Automatic Raw Data Processing Options

In this dialog you can select which operations shall be carried out during the automatic raw data processing. The dialog can either be opened by selecting "Configure..." from the "Pattern/Automatic" submenu, by pressing the corresonding keyboard shortcut <Ctrl+Alt+A> (<Cmd+Alt+A> on the Mac), or by pressing the corresponding button in the main toolbar. All steps are carried out (if applicable) in the order they appear in this dialog.

The following options can be set:

Strip K-Alpha2 contribution (if applicable)

By activating this option you can let Match! strip the K-Alpha2 radiation contribution from the diffraction pattern, if the wavelength suggests that such a contribution is present (e.g. Cu K alpha radiation, lambda=1.541874 A).

Subtract background

If this option (checkbox) is marked, Match! will remove the background radiation so that only the peaks remain in the ideal case.

Smooth raw data

This option tells Match! to smooth the raw diffraction data, using the well-known Savitzky-Golay algorithm (A. Savitzky, M.J.E. Golay, Analyt. Chem. 36, 1627-1639 (1964); corrected by Steinier, Termonia and Deltour in Analyt. Chem. 44, 1906-1909). This is generally adventageous if there is a lot of noise in the pattern, e.g. resulting from a poor counting statistics. On the other hand, smoothing of raw data may result in a loss of information, e.g. if the peaks of minor or trace phases are removed.
You can adjust the number of repetitions of the smoothing algorithm. By default, 2 loops are run, while only a single run is performed when the corresponding command in the "Pattern" menu or the toolbar button are pressed.

Background determination flexibility

If the automatic background determination does not give a satisfactory result, you can correct it. This should be done before running the peak searching command!
If the automatically determined background does not cover all structures, because the background is too “rigid” (in which case amorphous “humps” are not fully covered, leading to surplus peaks when using the automatic peak searching), you can correct this by pressing <Ctrl+F2> (which will increase the background flexibility).
If on the other hand the background is too flexible (profile areas that belong to the peaks are covered (i.e. hidden) by the background), you can decrease the flexibility by pressing <Ctrl+F3>, in order to make the background more rigid (cover less of the peak sockets), until the visual agreement between the orange curve and the estimated background is acceptable.

Peak Searching Method

You can select if either the normal peak searching function or the more accurate (but slower) profile fitting function (which includes a special peak searching method) shall be used for peak searching in raw (profile) diffraction data.

Default FWHM

If you are searching peaks using the normal peak searching function or import diffraction data as peak lists (i.e. only peaks, no profile data), the FWHM of the peaks is set to this value if the option "Determine automatically" to its right is not active, or if no raw/profile diffraction data are present. Otherwise, the default FWHM value will be determined automatically as an average from the raw/profile data during the normal peak searching.

Default Sensitivity for Peak Searching

You can adjust the default peak search sensitivity separately for the normal peak searching function or the profile fitting function using these two sliders. If you have modified the peak search sensitivity before opening this dialog (e.g. using the F3 or F4 function keys), the sliders will represent these new values when the dialog is opened. You can make the modified sensitivity values permanent by checking the "Save as defaults" checkbox at the bottom before closing the dialog by clicking "OK".

Automatically optimize sensitivity

You can let Match! optimize the peak search sensitivity automatically by marking this checkbox/option.

Correct 2theta error

Using this option you can decide if and how Match! shall try to automatically correct for 2theta errors, either using the zero point or the specimen displacement correction.

Save as defaults

If you enable this checkbox, the options and values defined on all tabsheets of the "Options" dialog will be stored in your registry so that they will be the same next time you execute Match!.