MODIFICATIONS OF THE SP-MC METHOD FOR THE COMPUTER-SIMULATION OF CHEMICAL-POTENTIALS - TERNARY MIXTURES OF FUSED HARD-SPHERE FLUIDS

The efficient recently proposed scaled particle Monte Carlo (SP-MC) co mputer simulation method for calculating the chemical potentials of ha rd body fluids at very high densities is modified and extended, with t he derivation of the modified method for pure hard spheres and their m ixtures, and for pure hard diatomics. The method is extended to a tern ary mixture of tangent heteronuclear diatomics and their constituent h ard spheres (the method is extended readily to mixtures of arbitrary f used hard sphere molecules and their constituent spheres). Detailed ca lculations have been made for a ternary system reported in the literat ure, composed of hard spheres of different diameters and their tangent diatomics. The present method is much more efficient than previous ap proaches. It was found that the difference in excess chemical potentia ls of the diatomics and the spheres is essentially independent of comp osition, a feature exhibited also by the Boublik-Nezbeda hard body equ ation of state, which slightly underestimates the simulation values.