[Ifeffit] Regarding dopant additions in ATOMS

[Bruce Ravel]

Andrew,

Feff only allows 8 kinds of atoms -- the absorber is number 0.  Then
you can have 7 other types of atoms in the calculation.

As for your question about dopants, check out this mailing list post I
wrote several years back:
  http://millenia.cars.aps.anl.gov/pipermail/ifeffit/2002-July/000092.html
Question 14 at 
  http://cars9.uchicago.edu/iffwiki/FAQ/FeffitModeling
carries on the discussion.

If, after reading those links and the material they point to, you
still have specific questions -- ask away and we'll try to answer.

Regards,
B


On Thursday 02 August 2007, Andrew Campos wrote:
> Hi everyone,
>
>
>
> I am having an issue trying to figure out a way to simulate the XANES
> environment using FEFF 8.4 for some catalyst we are working with. What I am
> trying to do is use different structures from  a crystal database which are
> from the Rietveld Structure Refinement method from the XRD patterns. The
> issue I'm having is trying to account for vacancies, which when compiling
> the crystal structure in ATOMS I think I am allowed to have 9 dopants (from
> the ATOMS manual, however it is saying there is an error past five dopants,
> all of which are null, but that is irrelevant I guess)
>
>
>
> " *** Warning at line  13
>
>       You have exceeded the maximum number of dopants.
>
>       ATOMS will ignore this and all further dopants.-"
>
>
>
> I'm wondering if there is a better way to account for site occupancies <1,
> or whether this is altogether a bad idea to try and simulate the XANES
> environment in the first place. ATOMS is a great program however I might be
> doing something wrong. I appreciate any insight anyone can give in this!
>
>
>
> Sincerely,
> Andrew Campos



-- 
 Bruce Ravel  ---------------------------------------------- bravel at anl.gov

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