Re : Le Bail method in GSAS
Lachlan Cranswick ( lachlan@dmp.csiro.au )
Wed, 31 May 95 8:17:26 EST
> From: Thomas.Hansen@cnrs-imn.fr
> Date: Tue, 30 May 1995 15:27:58 GMT
> Subject: Le Bail method in GSAS
>
> Very recently I have tried to use GSAS (van Dreelen) instead of FullProf for
> both Rietveld structure refinement and pattern matching. As for refinement it
> is okay, but I do not manage to extract structure factors after the Le Bail
> method. This method does not imply any structure model for obtaining structure
> factors out of a powder diffraction pattern, but GSAS asks everytime to
> introduce an atom position, also when I indicated that the Le Bail method
> should be used. I am sure that I made some error and I would be grateful if
> someone can help me to obtain reliable structure factors for structure
> determination also by GSAS. Please mail to this mailing list (rietveld@xtal.
> cmc.uab.edu) or to me (hansen@naimn2.cnrs-imn.fr or hansen@fluo.univ-lemans.fr).
> Thanks, Thomas Hansen, Laboratoire des Fluorures, Le Mans, France
>
I'm also a beginner on GSAS so anyone can feel free to correct
any of the following.
Just insert a single atom as the "dummy" structure and then
you will be able to do the Le Bail method with GSAS. This
can even be a hydrogen atom at any nominal position
(i.e., .179 .289 .489).
After you do the LeBail run, you can then use GSAS to
give a Patterson map if desired or plug the integrated
intensities into a direct methods program.
------
Does anyone know of a program for converting
the GSAS integrated intensity output from a GSAS
LeBail run into a format suitable for Shelx?
------
Lachlan.
-- Lachlan Cranswick _--_|\ lachlan@dmp.CSIRO.AUCSIRO - Division of Minerals /CSIRO \ tel +61 3 647 0367339 Williamstown Rd, \_.--._/ fax +61 3 646 3223Port Melbourne, Australia, 3207 v