Hello, I have a question about fitting an EXAFS dataset. The compound is FeAs2, crystalline, and will be used as a model for further study. I was able to fit the first three shells very well. However, when I try to fit the fourth shell, I either get amplitude that is too high (> 2, with large errors), or 0.0. There are several single-scattering and several multiple-scattering paths in that region. Sometimes, only excluding one of the MS paths leads immediately from amplitude of >2 to 0.0. I'd appreciate any advise about what is the meaning of these changes and the inability to fix the spectrum. Attached are few pictures from Artemis. Thank you, Juro Majzlan ---------------------------------- Juraj Majzlan Institute of Mineralogy and Petrology Albert-Ludwig-University of Freiburg Albertstrasse 23b Freiburg, D-79104, Germany telephone +49-761-203-6416 fax +49-761-203-6407 http://www.minpet.uni-freiburg.de