On the application of the EXP-like approximation for the description of the site-site ion-molecular models

Abstract

The site-site radial distribution functions for model ion-molecular systems within the framework of the exponential (EXP)-like approximation are presented and analysed. The ions and molecules are taken to be oppositely charged hard spheres and symmetrical polar hard diatomics or tetraatomics, respectively. The density-controlled ordering as well as the solvation and molten salt regions are discussed in terms of the site-site radial distribution functions. The characteristic features of the short-range order in these regions are determined by the interplay between the short-range and long-range ion-ion, ion-site and site-site interactions. The influence of the molecular shape and moleclar distribution of charge on the system short-range structure is shown. The reference hypernetted chain-like and the reference Percus-Yevick-Allnatt-like integral equations are proposed.