[Ifeffit] FEff

[Bruce Ravel]

On 09/29/2014 11:44 AM, Carlos Triana Estupinan wrote:
> Dear
> Feff group
>
> I am Carlos Triana, and I want ask you the following.
> I am trying to calculate the feff.inp file for a theoretical amorphous
> structure composed by a supercell with 24 Ti atoms surrounding by 48
> oxygen atoms with different coordination. In amorphous materials or
> materials with distortions from regular crystals, the absorbing atoms
> may have different surroundings.
> My question is how can I build the feff.inp file in this case, shall I
> define the 24 Ti atoms like absorbing atoms, because in this case the
> feff does not works.
> What can I do in this case, how can I build the feff.inp file with
> different environments
>
> I will be very grateful for your help

I'd like to follow up on Matt's comment.

I presume you have some way of knowing a list of Cartesian coordinates 
for the atoms in your cluster.  If so, the discussion on pages 7-10 of 
this talk should be helpful, with the caveat that your input file needs 
to be appropriate to the version of Feff you intend to use.

https://speakerdeck.com/bruceravel/modeling-non-crystalline-samples?slide=9

Make one input file for each Ti atom serving as the absorber.  As Matt 
said, take care not to overwrite your results.

Were this my problem, I would prefer to organize and perform N 
calculation, then add them up myself.  That said, Feff does provide a 
simple sort of configuration average.  Look up "CFAVERAGE" in the Feff 
document.

B





-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2
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