I have now removed the "beta" version of PC-GSAS and replaced the
"standard" version with the newest version. A few lines from the most
recent "GSASNews" follows:
GSAS News.......
Mar. 3, 2000
Some new things & fixes:
1. The atmdata.dat now contain the <jo> and <j2> magnetic form factor tables
from the Intl. Tables Vol. C. These are now read by GSAS to compute magnetic
form factors. The spin-orbit coupling is selected by setting the Lande g
factor.
2. The atmdata.dat file now contains anomalous neutron scattering factors for
selected elements & isotopes. These are mostly rare earths. The coefficients
allow calculation of the wavelength dependence of b' and b"; this is most
useful
for TOF experiments.
3. The "Stephens function" for microstrain broadening has been changed to
use the
correct multipliers for some of the contributing terms. The errors were
mostly for
rhombohedral/trigonal space groups.
4. The number of atoms allowed for a macromolecular structure is 5000.
5. There is now a "Marquart" style damping factor in GENLES. It is a multiplier
on the LS matrix diagonal elements. Useful values to try are between 1 and
2 in
case of severe ocsillations.
6. ORTEP & VRSTPLOT will not plot macromolecular structures. These structures
are too large to be handled by these programs. I recommend using Swiss PDB
Viewer
instead.
7. The atom delete function now works for macromolecules.
Some unfinished business:
1. A possible modification to the rigid body TLS model to be properly based on
a cartesian coordinate system.
2. Completion of the proper texture description for the m3 cubic space
groups. It
presently is approximated by the m3m model.
3. Using the anomalous neutron scattering data now available in the
atmdata.dat file
to properly compute wavelength dependent absorption coefficients for
elements with
resonances.
Now that this version is reasonably stable I plan on porting it to Linux
and other unixes that I can reasonably support. The Linux version will be
ported to RedHat 6.1 so you may wish to upgrade as appropriate.
As usual please let me know of bugs & features that you may find when using
GSAS.
Thanks,
Bob Von Dreele
