<> Hello Carlo et al, FEFF6 allows to use SS cards that were specifically designed to calculate single-scattering paths in the case the structural details are not known, as in Carlo's case. I am attaching a working example where I used to calculate single scattering FEFF in Cu-O in octahedral coordination in Cu2+[H2O]6 complex. I included hydrogen in the input file since it affects charge on oxygen, but in principle it works. Some details are given in this article: http://pubweb.bnl.gov/people/frenkel/HUMIC-EXAFS/est.pdf You can run FEFF6 using attached file and note that it produces three files, each corresponds to the single shell of Cu-O atoms. Note the use of the OVERLAP card in the attached file, as well as the use of Bohr's radius to work around the bug in FEFF6 that uses distances in OVERLAP as multiples of Bohr's radius instead of Angstrems, while the units in SS card are in Angstrems. Regards, Anatoly Anatoly Frenkel, Ph.D. Associate Professor Department of Physics Yeshiva University 245 Lexington Avenue New York, NY 10016 http://www.yu.edu/faculty/afrenkel Office: tel. (212) 340-7827 fax (212) 340-7788 anatoly.frenkel@yu.edu Laboratory: tel. (631) 344-3013 frenkel@bnl.gov -----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov]On Behalf Of Barton, David (DG) Sent: Wednesday, January 05, 2005 4:46 PM To: 'XAFS Analysis using Ifeffit' Subject: RE: [Ifeffit] Generating single scattering paths in Artemis Scott,

This can be fixed by editing the feff.inp file to remove the Fe potential 1, but that's not enough--the oxygen scatterers then have to have their potential renumbered to 1 to make things work. That's a lot of work to do what should be simple.

So I vote for changing the way Artemis works in such circumstances so that less editing is needed: if the absorbing atom is not present in the scattering list, then it shouldn't have a second entry in the potential list.

I second this vote, since I also have had this same problem. New users could become quickly disgruntled by the Fatal Error message when attempting to put in simple systems or just by choosing a short cluster distance to only include the first shell in the FEFF calculation. At a minimum, it would be nice if Artemis trapped this error and reported a more friendly popup error message. Dave _________________________________ David Barton, PhD. The Dow Chemical Company Catalysis R&D _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit <>