As I just mentioned to Matt, this conversation is NOT moot because a 
significant fraction of users have bought access.
I wonder if it would be possible to make some sort of 'crippleware' version of 
FEFF(>6) which ONLY runs from within DemLarchTemis?
That might make the UW folks a little more comfortable with letting it be 
available.

FEFF9+ will be a harder case because it seems to have been designed to be run 
by the jfeff interface and consists of separate programs
which have to be run in sequence.  I suppose a wrapper could be written to 
orchestrate that.
        mam

On 3/27/2013 5:44 AM, Bruce Ravel wrote:
On Tuesday, March 26, 2013 01:21:58 PM Matthew Marcus wrote:
Just to put my bit in, I believe that the most significant advantage of
higher FEFF versions for EXAFS analysis is that it results in more
reasonable values for E0 for high-Z elements.  I forget whether the issue
is high-Z scatterer or absorber.  If you use any of the common
prescriptions for defining E0 with, say, Pt metal in FEFF6l, your fit will
want large values of enot.  That said, I have not done a real test by
comparing FEFF8 and FEFF6 paths.  Has anyone done that?


This is *exactly* my point.  Except, as Matt said, for the rather
limited, unpublished tests made by him and John many years ago, no one
has reported on a substantive test comparing the efficacy of feff6 and
feff8 for analysis of EXAFS.  (Of course, computation of XANES and
other spectroscopies is a different topic entirely.)

Perhaps I would be more interested in fully implementing use of feff8
in my software if someone would offer a better justification than "8
is a bigger number than 6".

FWIW, I agree with Matt that the multi-pole self-energies is a very
promising thing that could have a substantial impact on EXAFS
analysis.  But few of those who claim to want to use feff8 with my
software are actually computing and using the multi-pole
self-energies.

In any case, I do not have permission to redistribute feff8.  So, on a
very real level, this conversation is moot.

B


It would be
interesting to know what happens if you simulate a k^n*chi(k) with one
program and fit it with the other.


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