Feburary 8, 1995
I have now revised the PC-GSAS version to take care of
the bugs that have been
reported to me as well as a few I've found on my own.
Moreover, there are some
enhancements as well.
1. The bug that gave a "divide by zero" for x-ray data
in all versions of GENLES
has been fixed for Alpha/VMS, VAX/VMS and PC versions.
Seperate GENLES.EXE files
are in their respective distribution directories for the
first two. I havn't
done the unix fixes for this yet.
2. The bug that crashed EXPEDT in attempting to set
diffractometer constant
refinement flags for x-ray data in PC-GSAS is fixed.
3. Minor typos in various places in EXPEDT have been
fixed for PC-GSAS. Other
versions will follow later.
4. PC-GSAS is now "optimized". GENLES now runs twice as
fast as the "unoptimized"
version released earlier. However, the optimizer does
make mistakes and there
may be new bugs that weren't in the earlier version.
Please check your
results and let me know what you find. One known bug is
that the atom search
routines in ORTEP fail in mysterious ways. It does not
crash but fails to find
atoms in searches over, for example, certain bond
distance limits. Despite some
effort this is not resolved.
5. PC-GSAS now has hardcopy graphics support for both
PostScript and encapsulated
PostScript. The latter hardcopy files may be inserted
into both MS Word and
WordPerfect documents. The plots are not visible (there
is no TIFF included) but
print fine. They can be resized within the document as
well.
6. PC-GSAS now requires VGA graphics exclusively. Thus,
it can be run in the MS-DOS
window in Windows 3.1 without conflict although some
machines will require it
to be "full screen".
7. The PC-GSAS is now available as a "self extracting"
exe file. This should
eliminate much of the difficulties people were having
with "binary" vs "ascii"
ftp file transfer. Instructions for installing it are in
the file
"[.dos]readme.dos"
As before, let me know how it goes.
January 20, 1995
Happy New Year to everyone. I hope everyone had a good
holiday. Now for the
long awaited news - I have placed the first PC version
of GSAS in the
"anonymous" ftp directory [anonymous.dos.gsas]. It has
been developed using the
Microsoft PowerStation Fortran to run on Intel i386 and
better (486 or pentium)
machines in MS-DOS. It uses a "DOS extender" to work
beyond the 640K limit up
to the full memory of your machine. I have tested it on
a 8Mb 33MHz i486DX2
system, a 16Mb 90MHz pentium system and a 8Mb 32MHz
i486DX2 laptop. All work
very well. In fact the original development was done on
the laptop machine. The
graphics required is VGA (or better) but I haven't
implemented any hardcopy
option. Virtually all routines in the Unix & Alpha
versions of GSAS have been
implemented so that both powder and single crystal data
can be processed.
Because there were extensive changes that had to be made
to the source, there
may be many remaining bugs that I didn't find during my
testing. If you find
something that fails or doesn't look right (even
spelling errors) please let me
know. Look at the file [.dos]readme.dos for installation
details.
Have fun with it.
November 15, 1994
All distribution kits for GSAS have been updated. There
were a few bug fixes
and a couple of new features that were in the new manual
that hadn't made it
into all the versions. The details:
1. The phase fractions are now given with the correct
esds by GENLES for all
histograms. The last version messed these up in some
combinations of multiple
phase/multiple histogram refinements.
2. The cell angle output in the setup part of GENLES is
fixed. In earlier
versions the gamma angle for hexagonal cells was given
as 90.00 deg; internally
the program used the correct angle.
3. Corrections were made the the single crystal routines
SCABS, SCMERGE, etc.
This mostly involved corrections to the crystal -
orthogonal transformations
and make the absorption corrections more accurate.
4. GENLES now reports a residual based on Fo^2 for
powder data anytime the
extraction flag has been set for a histogram. This is
similar to "R-Bragg"
but clearly defined to be as close to the single crystal
use as possible for
powder data.
5. GENLES now has the facility to refine the Ka2/Ka1
intensity ratio. The
parameter is named KRATIO and is found as a
diffractometer constant. Normally
the value is 0.5; if you don't wish to refine it, that
is the value GSAS will
assume.
6. A number of changes have been made to the contents of
the experiment file
in anticipation of implementing a "SIF" file output
routine for GSAS. Some of
these things are changed via new menu items in various
places in EXPEDT; none
are essential for normal operation of GSAS.
I have succeeded in producing a PC version of GSAS that
runs in MS-DOS via a
"DOS Extender" to enable use of the full machine memory.
It is not yet complete
and still needs considerable checking and debugging
before it can be released.
However, it appears to perform quite well even on a
33MHz, 486DX laptop,
including graphics! I would like to know what parts of
GSAS people would like
to see in such a version. I have implemented EXPEDT,
POWPREF, GENLES, POWPLOT,
DISAGL, BIJCALC, GEOMETRY, ORTEP, FOURIER, FORSRH and
FORPLOT. Let me know
what else you want.
September 1, 1994
The long awaited new GSAS manual is now done. It
consists of 4 Postscript
files which are in the directory [anonymous.manual]. You
can either download
the four original files (GSASMANUAL1.PS ..
GSASMANUAL4.PS) or take one of the
two backup style files (GSASMANUAL.BAK or
GSASMANUAL.TAR) and recreate the
original files on your machine. These files are in the
plainest type of
Postscript I can manage but they contain the full manual
including drawings.
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.
May 2, 1994
There is now a distribution kit available for HP-UX. It
is identical to the
other version released earlier. As this is a first
release for the HP, there
may be bugs that don't show up in the other versions
despite the fact that it
has passed all our QA tests. Those of you that use it
please let us know of
any bugs or problems.
Apr. 18, 1994
The newest versions of GSAS for VAX/VMS, Alpha/VMS, SGI
Irix and DEC Ultrix
have been placed in their respective directories. This
is the first
consolidated distribution so we would like to know of
any difficulties you may
have in retrieving the kits and installing them. There
is not a kit for HP-UX
at this time.
Changes to GSAS:
1. New hard copy device for "EPS" postscript. This
output can be put directly
into PC or MAC word processor documents (Word, etc.)
2. New adjustible X-windows device (graphics option
"H").
3. Maximum no. of background terms is 36. This is not
tested to its full extent
for any of the background functions. You should expect
that some of the
functions may fail in odd ways (overflows, etc.) for
very large numbers of
terms; so beware.
4. A rationalization of the GSAS standard for the choice
of orthogonal
coordinate system. We had at least three different
conventions; now there is
just one.
5. There is a fix to the preferred orientation
calculations. It was in error
for non-centrosymmetric space groups. This is now fixed.
6. Remove extraneous output file from ORTEP.
7. Replace all "free format" WRITE, TYPE, etc.
statements with formatted ones.
8. Make the colors that appear on various graphics
devices more uniform.
9. Fix a bug involving "unobserved" reflections in
FOURIER.
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!