Theory of Fused Salts

Abstract

The properties of ionic pair distributions are investigated for a simple fused‐salt model. The short‐range ion core forces are assumed to be identical for both anions and cations and, although the method is capable of handling mixtures of ions with different charges, only a single fused salt of the symmetrical‐valence type is considered. A set of relations is developed to describe the asymptotic behavior (for large ion distances) of the ion pair distribution functions. These relations are obtained with benefit only of certain weak, plausible assumptions concerning the triplet superposition defects; as a consequence, the usual superposition approximation of liquid theory is circumvented. A significant feature of the results is prediction of concentric shells of average charge density surrounding a given ion in a manner suggesting local latticelike structure.