A practical introduction to multiple scattering theory

In recent years, the ability to interpret and analyze X-ray absorption spectroscopy data has progressed dramatically due, in large part, to the rapid development of ab initio theories of the absorption spectrum. One such theory, the feff program, has proven especially successful and is in wide use throughout the world. This paper presents an outline of the real-space, multiple-scattering theory used by feff and explains how feff is applied to both the near-edge and extended portions of the absorption spectrum. This paper is intended to be both practical and accessible. It is by a synchrotron experimentalist and intended for synchrotron experimentalists.