[Ifeffit] (no subject)

[Matt Newville]

Dear Cammelli,

What (if anything) did you refine from the FEFF calculations?  You
would definitely want to refine E0 (origin of k) as a) E0 is usually
chosen on the data in a fairly arbitrary way (say, maximum of 1st
derivative)  and b) the calculations for E0 (even in Feff8) may be off
by a few eV. Such an E0 shift would cause a slight shift in the
k-space spectrum.   You might also need to refine an overall amplitude
factor or an energy width.

Beyond that, what are your goals for simulating the Cu spectra beyond 8Ang?

To simulate this spectra well that far out, you'd definitely want to
look into what thermal disorder parameters to apply.  That's an
interesting topic of study, but not an easy task to do with good
accuracy for these multiple scattering paths.

--Matt

On Mon, Mar 2, 2009 at 7:59 AM, Cammelli Sebastiano
<Sebastiano.Cammelli at psi.ch> wrote:
> Dear Feff user
>
> I had a problem trying to simulate the EXAFS spectrum of a Cu foil. I found
> a small shift in the k space and I do not know if it is significant and, if
> it is, how to correct it.
>
> In the doc file I attached you will find the details of the problem, the
> feff.inp and some explications. Do not worry about its size, pictures are
> large and the feff.inp takes space…
>
> Thank you a lot for your help
>
> Sebastiano
>
>
>
> Sebastiano.cammelli at psi.ch
>
>
>
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