New release of GSAS

VONDREELE@gov.lanl.lansce.mist
Fri, 17 Jun 1994 16:07:18 -0600 (MDT)

GSAS News.......

June 17, 1994
All distribution kits for GSAS have been updated. There have been a number of
bug fixes and minor modifications. Some were done in anticipation of a new
release of the manual. There are also a few new features that have been added
to the system; a short list of details follows.

Changes to GSAS:
1. The "timeout" period for the distribution machine, MIST.LANSCE.LANL.GOV, has
been extended to 10min. This should help with some difficulties people have had
in ftp transfers particularly overseas.
2. FPRIME on VMS systems is working again. There was a mixup between VMS and
UNIX sources in the last release.
3. GENLES now produces a unit cell formula weight and calculated density based on
the actual unit cell contents including atom site fractions. This output appears
after the refined atom parameter listing for each phase. No esd is given for these
values so use them with due consideration of the errors in the atom fractions and
the errors in the "standard" atomic weights.
4. GENLES now produces a weight fraction associated with each phase fraction. If a
phase was subject to a "leBail" extraction, the weight fraction will be reported
as zero. As with #3, no esd is given.
5. For those of you who use the GSAS library to link to your own codes, there is in
the [anonymous] directory the file "gsas_glossary.lst" which may help. It contains
the argument list for all the routines in GSAS along with a short (although sometimes
nonexistent!) description of what the routine does.
6. The powder absorption now includes two additional choices for two versions of
a surface roughness correction. One is by Pitschke, Hermann & Mattern and the other
is by Suortti. Both give essentially identical results and will frequently make
a dramatic improvement in the values of thermal parameters obtained from Bragg-
Brentano x-ray data. In some of my tests the Uiso's from x-ray data came very close
the the neutron values (which of course are correct!) Refinement of them will proceed
a little oddly since both the scales and U's must shift to compensate so GENLES will
give the "diverging refinement" message a few times as these things get to their
new values.

We thank all of you that have pointed out the various bugs, errors, etc. Many
of the above fixes resulted from your input. Please keep 'em coming!