[Ifeffit] Possible bug in atoms files generation by Artemis

Matthew Marcus mamarcus at lbl.gov
Wed Mar 27 10:41:11 CDT 2013

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.

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 limited, unpublished tests made by him and John many years ago, no one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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