[Ifeffit] Larch 0.9.53

[Matt Newville]

Hi Folks,

Larch 0.9.53 is now available for download and use.  Although the last
announcement here was in April for version 0.9.51, there have been several
improvements especially to the XAS Viewer application since the last
release, mostly in anticipation of upcoming workshops and short courses.

 - There are important fixes for reading Spec/Bliss HDF5 files from ESRF -
thanks to Mauro Rovezzi for this.  You can now import multiple XAS spectra
from Spec/HDF5 files.

 - XAS Viewer now supports doing Feff6l or Feff8l calculations and has a
GUI interface for doing a Feffit fit to a sum of Feff paths.  In the
current GUI frame, this is limited to analyzing one dataset at a time.
This brings up a related feature:

 - A database (sqlite3) of CIF structures from the American Mineralogist
Crystal Structure Database (http://rruff.geo.arizona.edu/AMS/amcsd.php) is
included.  The version of this database in the source code contains about
9000 structures.  If your machine is well-connected to the internet and can
reach https:/millenia.cars.aps.anl.gov, a more complete version (~30 Mb)
with 20,000 structures will be downloaded and used.  To be clear, the 9000
structures in the smaller set are probably sufficient -- what is removed is
some CIFs from publications with many similar structures (T or P
dependence) or structures so large and complex that they will be hard to
make into single Feff files.

 - The CIF files from this DB or other CIF files (well, CIF is notoriously
variable!) can be automatically converted to Feff input files (using python
tools from the Materials Project, modified a bit).  Because many of these
CIF structures contain fractional occupancy, that is handled (probably
poorly, but at least not failing) by randomly selecting atoms based on the
site occupancy.

 - XAS Viewer has a CIF Browser (from the Feff menu) where you can browse
by mineral name, included atoms, etc. From that you can generate a
Feff6l or Feff8l input file, potentially edit that input file, and run Feff
to generate path files. These will be organized in your home folder
(C:\Users\Name\larch\feff for most Windows users, $HOME/.larch/feff for
Linux/MacOS).  There is also a Feff browser to select Feffnnnn.dat files
from your previous Feff runs and bring them into the "Feffit" tab in XAS
Viewer to use in the sum of paths fitting of EXAFS spectra.

Of course, all of this Feff and Feff fitting interface should be viewed as
"initial release" and comments, suggestions, and bug reports are welcome.
The notes above are approximately the extent of the documentation, though
some videos of using this will be publicly available in a few weeks.

There are updated binary installers for Windows, MacOSX, and Linux. There
are also updated "GetLarch.sh" and "GetLarch.bat" scripts that also
hopefully fix any earlier problems.  If you have any questions, problems,
or suggestions, please let me know.

--Matt
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