Spatial correlations of interatomic voids in molecular liquids studied using Delaunay simplices

Abstract

Pair correlation functions are calculated for interatomic voids determined using Delaunay simplices. Various modifications of these functions are suggested in relation to the problem formulated. In the simplest case, this correlator is a conventional radial distribution function g(r), but its calculation employs the centers of voids, but not the centers of atoms. For analysis of nonuniform systems, it is suggested that a “weighted” radial distribution function be used, where pair distances are taken with weights that depend on the volume of the voids. To study structural differences between molecular liquids (e.g., alkane isomers) we use the partial radial distribution functions that take into account only relatively “wide” voids. The ion-void distance distribution functions define voids in the hydration shells of ions an aqueous salts.