On the simulation of thermodynamic and structural properties of simple liquids

Abstract

This work, which is purely methodological, demonstrates new applications of perturbation methods in computer simulations of simple liquids. Most applications are based on the calculation of bulk and local excess chemical potentials of one or several inserted test particles, using a Widom technique in the canonical ensemble. This gives a powerful tool for obtaining distribution functions, some of which are virtually impossible to determine with other techniques. Results are also presented for single-ion activity coefficients and Donnan potentials. A perturbation approach is used to calculate thermodynamic response functions with respect to particle number, temperature, and volume changes. The applicability is exemplified by studies of hard-sphere fluids, uniform and nonuniform electrolyte solutions within the primitive model, and screened Coulomb systems.