Carlos, you can only have one absorbing atom in a feff calculation. You must run each atom separately if you want an average structure for the the amorphous material. 24 feff calculations with each Ti as the absorber. Then average the spectra. Anyone else have a better method? hth, Chris ******************************************** Dr. Christopher Patridge Assistant Professor of Chemistry Dept of Math and Natural Science D'youville College 320 Porter Ave., Buffalo, NY 14201 Phone: 716-829-8096 Email: patridgc@dyc.edu On Sep 29, 2014, at 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

-- Carlos Augusto Triana Estupiñan (C.A. Triana-E) Physicist M.Sc. In Physical Sciences-Research PhD Student-Research Ångströmlaboratoriet, Lägerhyddsv. 1 Solid State physics Uppsala University, Box 534 751 21 Uppsala, Sweden Tel: +46 018 471 3144 e-mail:carlos.triana@angstrom.uu.se web:http://www.uu.se/

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

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@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/