Ab-initio Modeling of X-ray Absorption-spectra

A new method for analysing X-ray absorption spectra using multiple-scattering theory is presented. The basic principles and some applications are briefly discussed focusing the presentation on the general relevance of this approach. The GNXAS set of programs, especially designed to perform structural analysis on absorption data of any system, is described showing the practical applicability of the theory. The applications presented show that reliable and unique structural information on pair and higher-order distribution functions can be obtained by using this method which takes proper account of the multiple-scattering contributions.