The input space group symbol is first checked against the look-up table SGINFO.DAT. If no match is found, an error message to this effect is issued. The Herman-Mauguin symbol is then converted to the Hall symbol, and the symmetry matrices derived from this using the GETSPEC routines of Brown and coworkers.
The character string for the input symbol is case-insensitive. The SHELXTL syntax for subscripts may be used, but is unnecessary. Example syntax is:
P21/C P2(1)/c P 1 21/c 1 P1121 cmm2 I 4/m m m P 32 2 1 R-3:hThe last example show how you may explicitly specify the setting, for those cases where International Tables allows more then one setting. In this example the space group R-3 on hexagonal axes is indicated. For more details of the conventions used for various settings, see here
WinGX uses the Hall symbol internally, since this is an unambiguous indicator of space group type.