...add an option to our crystal structure drawing program DRAWxtl that would represent magnetic spin vectors with an arrow.
It might be easiest to follow the way one of the Rietveld programmes describes magnetic spins eg the original Rietveld code (in Lachlan's WWW museum I think) only required the spin vectors for individual magnetic atoms to be described, without knowledge of the full magnetic group symmetry.
However, drawing spin vectors is often done as a check on the magnetic symmetry, so not specifying the full magnetic symmetry may defeat the purpose of the exercise :-)
There are also a number of applications that already draw magnetic structures with full respect for magnetic symmetry eg Jane Brown's MVENTR "To draw magnetic structures in 3D in SGI inventor format" which is built on CCSL, the Cambridge Crystallographic Subroutine Library - see: http://www.ill.fr/dif/ccsl/appenx/mventr.html#MVENTR Jane has recently made a stand-alone Macintosh application outputting in open-GL. An earlier application which ran on unix used VRML, which was what you would want (see examples on http://www.ill.fr/dif/3D-crystals/magnets.html )
For Windows (and other systems) Bachir Ouladdiaf et al at ILL have recently produced an IDL module for the LAMP package, which is available in run-time versions for various operating systems -Windows, Mac-OSX, linux, etc... on ftp://ftp.ill.fr/pub/cs/
Alan.
Dr Alan W. Hewat, Diffraction Group Leader.
Institut Laue-Langevin, BP 156X Grenoble FRANCE 38042
fax (33)4.76.20.76.48 tel (33)4.76.20.72.13 (or .26 Mme Guillermet)
<[EMAIL PROTECTED]> http://www.ill.fr/dif/AlanHewat.htm
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