MOLECULAR-DYNAMICS STUDIES OF LENNARD-JONES LIQUID-MIXTURES .6. TEMPERATURE, DENSITY, AND UNLIKE INTERACTION DEPENDENCES IN STATIC AND DYNAMIC PROPERTIES OF BINARY EQUIMOLAR MIXTURES

Molecular dynamics calculations have been made for pure fluids and binary equimolar mixtures each containing 108 Lennard-Jones particles. The purpose of the calculations is threefold. First, the effect of the attractive term on the dynamic properties of liquids has been examined at fixed temperature and number density with equimolar mixtures of three models in which different combining rules for the energy parameter are assumed. Next the temperature and density dependences in static and dynamic properties of Lorentz-Berthelot mixture have been investigated. The variation of the velocity autocorrelation function with temperature and number density has been examined in detail. The activation energy for self-diffusion at constant number density is almost independent of the strength of interparticle interaction and is estimated to be 0.35 kcal mol-1, which is comparable with that for argon. In spite of remarkable change in the pattern of velocity autocorrelation function in the density range studied, self-diffusion coefficient changes linearly with density. Finally, a preliminary calculation on the microscopic process of mixing has been described. © 1980 American Institute of Physics.