Structure of molten alkali chlorides

Abstract

The structure of molten alkali chlorides has been studied by molecular dynamics simulation. A comparison is made of rigid-ion and shell models of the interionic potentials. It is shown that the effect of the polarizability of the ions is small when the two ions have similar sizes but is substantial when the cation is relatively small and unpolarizable. For NaCl the use of polarizable-ion potentials yields significantly better agreement with experiment whereas for RbCl it does not appear to be important for the structure. The excess number and excess charge fluctuations for the polarizable-ion model of NaCl are presented.