Structure and thermodynamic properties of molten strontium chloride

Abstract

Self-consistent calculations of pair distribution functions and thermodynamic properties are presented for a pair potentials model of molten strontium chloride. The calculations extend to a strongly asymmetric ionic liquid, an earlier assessment of bridge diagrams in a modified hypernetted chain approach to the liquid structure of alkali halides. Good agreement is found with computer simulation data obtained by de Leeuw (1978) with the same set of pair potentials, showing that the present approach incorporates genuine general features of liquid structure theory for multicomponent liquids with strong relative ordering of the component species. It is further shown that the strong correlations between the divalent cations, both in the model and in real molten strontium chloride, can be approximately reproduced on the basis of a simple one-component-plasma model, provided that dielectric screening is allowed for in the real liquid. This allows the authors tentatively to attribute the significant level of disagreement between a pair potentials model of this liquid and the neutron diffraction data of McGreevy and Mitchell (1982) to many-body distortions of the electronic shells of the ions.