LAUSR

Abstract Alkali and halide ions are seemingly simple chemical particles: spheres with plus or minus charges of 1 esu. There is, however, a large set of properties impossible to predict by this simple model. Molecular simulation is a suitable tool to test the performance of different models trying to grasp numerous features of these ions in solid, liquid, or gas phases, in pure state or solvated. While the internal energy and density of the crystal and the melt can be estimated by different models with acceptable accuracy, the melting temperature is a more elusive property being highly sensitive to fine details of the interactions. In this paper we device a set of potentials where the fit is carried out for the internal energy and density of ambient crystals with accurate melting temperatures. The ions have non-polarizable Gaussian charges with r-6 attraction and exponential repulsion. We present the results and discuss the difficulties of the process.