Hi Eckhard, you need to add the following two cards to your feff.inp files: * Self consistent potentials. This can be important for XANES calculatoins. SCF rscf 0 * Full multiple scattering (sums all paths within rfms). This is essential for * most XANES calculations. FMS rfms 0 calculations should be converged w.r.t. rscf and rfms, but for your files, you can just include the whole cluster of atoms. Also, I ran both files and the first one (gypsum) complains that atoms are very close together. FEFF does not crash, but I would check your structure to be sure that it is correct. Cheers, Josh Kas

Hallo @all,

(first at all, sorry for my bad english)

i'm a student working on my diploma thesis (nexafs/xanes) and my job is to simulate with FEFF 8.4 spectra, for example absorption as a function of energy (mu_(E)). I'm a newbie in this topic and i tried to get the k-edge of Sulfur for the substance gypsum (CaSO4 * 2(H2O)) and pyrite (FeS2). I'm interested in the XANES-range of the spectra not the EXAFS. I get everytime my peaks at ~2472 eV for Sulfur as absorber whatever substance i use (gypsum, pyrite,...). There are no differences with the peak position on the energy-scale or shifts. I'm really confused :-( I think, there should be differences in the spectra... I send you two feff.inp files from my feff-runs. My source is the mineralogy database (http://rruff.geo.arizona.edu/AMS/amcsd.php) where i get the data for the unitcell. Then i put the data in the XtalDraw program to get the positions of the Atoms in Angstrom, by the way i get i nice 3D-View of the unitcell :-). Then i put the values of the positions into feff... I simulated pyrite with 12 atoms and gypsum with 48. I'm appreciative for every help :-)

ciao, Eckhard

--------------------------------- Eckhard Bosman e.bosman@stud.uni-goettingen.de +49 (0)551-39-14441 Raum: E0.104 Institut f?r R?ntgenphysik Friedrich-Hund-Platz 1 37077 G?ttingen Germany