The User Database

As has already been mentioned, phase identification from powder diffraction data generally requires the availabilty of a so-called "reference pattern database". In many cases, this is the PDF database provided by ICDD. However, there are also alternative sources of reference patterns, like the COD database delivered with Match!, the previous ICSD/Retrieve versions, or even your own diffraction data.

While the COD reference database can be downloaded "ready-to-use" from the Crystal Impact web page free-of-charge, the ICSD/Retrieve or your own diffraction patterns must be imported into a so-called "user database" (file with extension "*.mtu") which can then be selected in the "Create Reference Database" dialog. The way to create the mtu-file depends on the kind of data source you would like to use:

Once you have created your user database file (*.mtu), the procedure to use it as reference database is pretty similar to the one using an old PDF-2 version:

First, you have to tell Match! that you would like to apply a user database, by marking the corresponding option in the middle of the Create Reference Database dialog. Afterwards, you have to select the location of the *.mtu file, by pressing the button "Select user database file (*.mtu)" to the right of the corresponding input line "Location:".

A "File Open" dialog will be displayed in which you have to select the mtu-file in which your user data are stored. Afterwards, press "Open" to select the file/directory and return to the "Create Reference Database" dialog. The location of the mtu-file will now be displayed in the corresponding input box.

If you like, you can now change the name of the new reference database at the bottom of the dialog (deactivate the corresponding "Automatic" checkbox first!), and/or change the location (directory) in which the index files for the new reference database shall be stored. Normally, Match! will automatically create a suitable name and select an appropriate directory.

In case you have administrator privileges, you can also select if you would like to make the new reference database available to all users (or only to you), and if you would like to make it the default Match! reference database for new users on your PC.

Once you have made your selections, press the "OK" button at the bottom to start the creation of the index files. A small window will display the progress of the indexation. The procedure will take a few minutes, depending especially on the number of entries as well as the drive access and processing speed of your computer. When the indexation has finished, a corresponding message will be displayed.

Afterwards, the new reference database will appear in the list of the Reference Database Library, ready for being selected. If the new reference database is the only one available in the Reference Database Library, it is selected for being used automatically. Otherwise, you have to select the new reference database manually: Simply mark (click) on the corresponding line in the table, then press "Select". The new reference database will be marked as selected, indicated by the ">>>" arrow on the left-hand side of the corresponding line.

You can now leave the Reference Database Library by pressing "Quit" and apply the new reference database in phase identifications and database retrievals.

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