[Ifeffit] Debye-Waller factors for MS paths

[Carlo U. Segre]

Matt, Peter, et al.

On Wed, 14 Jan 2004, Matt Newville wrote:

>
>Similar work has been done (or is being done) by N. Dimakis and G.
>Bunker (I'll probably get in trouble for calling them similar, as
>the approaches are pretty different, but both aim to calculate EXAFS
>DWFs from nearly first principles).  I believe
>  N Dimakis and G Bunker, PRB 65 201103(R) (2002)
>
>is the place to start.  To me, this work seems to be a little more
>straightforward to parameterize for a fit, but it would be real work
>to try to put such capabilities into ifeffit.
>

I am suspect that Grant Bunker reads the list but if he doesn't I can at
least tell you what I know.

Their method uses first principles to calculate DW factors for target
molecules (imidazole, for example).  They then use these calculations to
parametrize the DW parameters for systems containing this molecule.  It is
an extremely computationally intensive approach which may or may not be
possible for extended solids.  However, for molecules, it is very
promising because you can build up a data base, determine analytic
parameters and then use it for all similar molecules.

Carlo


-- 
Carlo U. Segre -- Professor of Physics
Associate Dean for Special Projects, Graduate College
Illinois Institute of Technology
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