[Ifeffit] FEff

Bruce Ravel bravel at bnl.gov
Mon Sep 29 11:48:04 CDT 2014

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.


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 


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

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2
  Building 535A
  Upton NY, 11973

  Homepage:    http://bruceravel.github.io/home/
  Software:    https://github.com/bruceravel
  Demeter:     http://bruceravel.github.io/demeter/

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