Thermodynamic and structural properties of liquid ionic salts obtained by Monte Carlo computation. Part 1.—Potassium chloride

Abstract

The equilibrium properties of liquid potassium chloride are simulated by a Monte Carlo model consisting of 216 particles interacting according to pair potentials of the form ϕ(r)=ar^–1+b exp (–Br)–cr^–6+dr^–8 with constants derived from the properties of the solid at 298 K.¹ The internal energy, pressure, molar heat capacities, temperature coefficients of pressure and volume, compressibility and entropy, as well as radial distribution function, are computed for 24 V,T points lying on one solid phase (1045 K) and four liquid phase (1045, 1306, 2090, 2874 K) isotherms at pressures up to 5 kbar. The calculated quantities which include the normal melting point and some experimentally inaccessible data, are in good agreement with the available experimental results. The resolution of the radial distribution function into contributions from different types of ion pairs provides new information about the structure of the liquid salt.