XAS in Liquid Systems

The phase diagram of elemental substances, molecular systems or mixtures display temperature/pressure (T, P) regions of stability of a condensed liquid phase in which the elemental units are able to diffuse throughout the occupied volume V, still forming a connected network of short-time living bonds. In classical molecular dynamics, the interaction potential is usually expressed as a simple sum of pair potentials. However, to improve the performance of the simulations more sophisticated empirical potentials including many-body contributions have been developed. The main advantage of many-body treatment over the conceptually and practically simpler pair-potential description is the ability to better reproduce some experimental properties. The data analysis of the x-ray absorption spectroscopy (XAS) spectrum from liquid systems presents a challenge that has been often overlooked. Traditional methods based on the Fourier filtering of a particular distance range spoil the information contained in the signal.