Extended X-ray absorption fine structure (EXAFS) spectra contain information about the local, molecular type structure, whereas (X-ray) diffraction (XRD) data reveal the periodic structure or long-range order (crystal structure) of materials. Variations in local and periodic structure greatly influence materials properties and related applications. However, data analysis often is performed...
I will discuss some aspects of the theory and simulation of x-ray absorption spectral shapes. Concerning machine learning approaches, a complication is that the most accurate methods take too much time, so they ideally should be approximated in a reliable fashion. We can distinguish 3 different starting points for the interpretation of XAS spectral shapes:
(1) Closed shell systems can be...