The application of the HNC/MSA approximation to bulk electrolytes

Abstract

The HNC/MSA integral equation, where the hypernetted chain (HNC) kernel is replaced by the mean spherical approximation (MSA) kernel is applied to a model bulk electrolyte consisting of charged hard spheres in a uniform dielectric medium. The thermodynamic functions which result from this hybrid integral equation are better than those of the HNC equation at low concentrations and only slightly worse than those of the HNC equation at high concentrations. At low concentrations, the HNC/MSA radial distribution functions are qualitatively better than the HNC values. In particular, there is no peak in g++(r) near r = 2σ. Quantitatively, the HNC/MSA g++(r) appears to be an overcorrection of the HNCg++(r). © 1983 American Institute of Physics.