Dear Bruce, I have a question about ATOMS application. I would like to get input file of stoichiometric SrBi2Ta2O9 (SBT) and off-stoichiometric Sr0.8Bi2.2Ta2O9(offstoich-SBT) with space group of A2 1am. How can I get the right crystal coordinations by changing the atomic concentrations; i.e. decreasing Sr to Sr0.8 and increasing Bi2 to Bi2.2 in off-stoichiometric Sr0.8Bi2.2Ta2O9 ? Best Regards

-- O. Murat OZKENDIR

I have forwarded this to the Ifeffit mailing list, which is the right place for questions like this. Here's some info about the mailing list as well as some hints on how to get more information about XAFS: http://cars9.uchicago.edu/ifeffit/BruceRavel/FormLetters/HelpRequest You question seems a little unclear and open-ended. Question 15 at http://cars9.uchicago.edu/ifeffit/FAQ/FeffitModeling might help. Perhaps someone else on the list has some advice for you. B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 My homepage: http://xafs.org/BruceRavel EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/