
PROGRAM GETSPEC

PURPOSE
This program calculates the symmetry operators (general positions) and 
special positions for any setting of any space group based on the 
Hall space group symbol which is setting specific  (S.R.Hall (1981) 
Acta Cryst, A37, 517-525).  The input may also be given as a 
Hermann-Mauguin symbol in the setting-specific form used by the 
Inorganic Crystal Structure Database.

The output lists the special positions with their multiplicities, site 
symmetries and all equivalent coordinates.  Wyckoff letters are not 
given as they cannot be assigned algorithmically.

DETAILS
The algorithms used are given in the paper `A real-space computer-
based symmetry algebra' by U.D.Altermatt and I.D.Brown, Acta Cryst 
(1987) A43, 125-130.  The program is supplied as Fortran source code 
in two files, GETSPEC.FOR (44kB) and GTSPLB.FOR (85kB).  A data file, 
SPGR.DAT (32KB), containing a concordance of Hall and Hermann-Mauguin 
symbols is required at run time.  The program is designed so 
that the subroutines can be incorporated into other programs.  
Further documentation will be found in the source code.

OWNERESHIP
This program is copyright by U.D.Altermatt and I.D.Brown.  It may be
used for private purposes and may be incorporated into freeware
providing that the comments concerning authorship and ownership
are not removed from the code.  For information about commercial
licensing, please contact I.D.Brown (see below).


CONTACT
For further information on this program, contact

	Dr.I.D.Brown
	Brockhouse Institute for Materials Research
	McMaster University
	Hamilton, Ontario, Canada L8S 4M1

	Fax +905-521-2773
	Email idbrown@mcmaster.ca


