Estimations of realistic LJ parameter and structure of gas-liquid interface for Kr by canonical Monte Carlo simulation

Abstract

We proposed the dual translation (DT) method for the canonical ensemble Monte Carlo (MC) simulation. In this method, two types of particle translation are randomly used in a fixed proportion on the MC process. Although very simple, the method permits the study of molecular configuration at whole area of system consist of liquid/solid, vapor, and their interface regardless of extreme localization of molecules. The method was applied to a plane surface of Kr at the boiling point. Two parameters in Lennard - Jones potential were determined by pilot simulations using the literature data of liquid density and atmospheric pressure. Resulting equilibrium pressures were similar, even if the initial configuration of molecules was drastically changed, showing solidness of the method. Heat of vaporization and surface tension were estimated using the Clapeyron - Clausius equation and the Kelvin equation respectively, and good agreements were found with literature data. It is confirmed for an extremely localized molecular system, that an equilibrium configuration is satisfactorily estimated by the DTMC simulation. It can be utilized for a gas adsorption system instead of conventional GC (grand canonical) MC.