Hi, I have been struggling with a tricky problem and cannot resolve it - hopefully someone out there can help! I have collected fluorescence XANES and EXAFS at the Se K-edge and I'm currently trying to fit the EXAFS (see attached files). The XANES agrees very well with a number of my standards and shows that the vast majority, if not all, of the Se is present in this material (an amorphous oxide-based system) as Se4+. I have tried to fit the EXAFS using a single Se-O path from a range of cif files (the simplest being SeO2). Other ions than O present incorrect bond lengths and I am convinced the first shell is oxygen. I can obtain a decent fit in terms of most parameters, as long as I disregard the consistently high value of Enot. Guidelines indicate that Enot should be less than about 5(ish), but I consistently get values of 10-12 when I try to fit my spectra, of which one is present in the attached files. I have checked my background subtraction and tried as many different options, changes and tweaks that I know or can find suggested (too many to list here) but I cannot obtain a fit with Enot below about 10 and so I ask my colleagues out there who are more experienced than I with EXAFS - can anyone shed any light on (a) the potential cause/s and (b) any potential solution/s? Thanks in advance for your time. Best Regards Paul Bingham -- Dr. Paul Bingham Immobilisation Science Laboratory Dept. of Engineering Materials University of Sheffield Mappin Street Sheffield S1 3JD UK Email: p.a.bingham@sheffield.ac.uk Direct Line: (0114) 2225473