This command is only available on the Windows platform, since 'Diamond' is a Windows program.
You can easily transfer the crystal structure(s) of the entries that are currently marked in the candidate list or match list into Diamond, the well-known software for crystal and molecular structure visualization. You can then use Diamond's large amount of elaborate tools and functionalities to create a structure picture according to your requirements, or to analyze and understand the building principles of the structure in detail.
If you do not have a Diamond license, you can use the Diamond demonstration version which can either be installed from the Match! Installation CD or downloaded from here.
In order to export the crystal structures of one or more entries into Diamond, simply mark the corresponding entries in the candidate list or match list, then select the "View in Diamond" command from the "Entries" menu. Match! will automatically export the marked entries to a temporary cif-file which is passed to Diamond afterwards. Even if there is more than a single marked entry, all crystal structures are saved in a single file.
As alternatives to the command in the "Entries" menu, you can also use the corresponding toolbar button in the main toolbar at the top, or the corresponding commands in the context menu of the candidate list or match list.