Dear All, I am new to XAFS data analysis and have very limited knowledge about using modelling structures for XAS analysis. I am not sure as to if this question is directly related to Demter or XAFS analysis as such but its a part of it for sure. * Question number one* I am trying to analyze the sample I recently collected at SPring-8 facility. The structure I am hoping to be formed during the reaction is more of a organometallic complex at silica interface. In order to establish the structure I was told that there are two methods I could use. 1) Use a counter part compound which is exact/looks like the structure I am hoping (so basically known compound) and then do traditional comparison method to establish the structure. UNFORTUNATELY I cannot synthesize such compound in lab nor such material is available in literature ( including crystal structure). 2) is to use the model. right now for modelling such structure I am using Spartan program (again I have not used it earlier in my graduate work) So I want to know as to how to generate the models in order to get the correct crystal parameters? (atoms positions?) Is spartan good enough to do job? is there any other method for doing such fitting? * Question number two* In order to get lower E0 values after the fitting, I read that there is a method to use in which delE value can be set to 0 intentionally and then recalibrating the spectra in athena again in order to accurately calibrate the E0. I read paper by Shelly kelly and Bruce Ravel. Also I have seen the steps in one of shelly kellys PDF formatted lecture, although I am still not sure about the exacts steps to take in order to do such calibration. Could someone explain me the steps in details (especially taking artemis files to athena and then using it as STD spectra for calibration purposes, I am confused about that) Thank you very much everyone in advance for your patience to go through such a long email and helping to solve my silly doubts. Your New Bee in this fantastic group Pushkar