Approximate evaluation of the dielectric constant for hard nonspherical molecules from Monte Carlo simulations

Abstract

Alternative exact expressions for the dielectric constant of a rigid polar fluid are evaluated approximately employing new Monte Carlo results for the pair distribution function of hard heteronuclear diatomics. The primary innovation of this work is to proceed beyond formal theories of the dielectric constant to explore possible approximation schemes that make use of Monte Carlo data on asymmetric molecules to obtain numerical results for dense molecular fluids. Each of four exact expressions are evaluated, ignoring the presence of dipoles and including only the effects of the asymmetric core. In this approximation, it is found that the Kirkwood–Onsager and Nienhuis–Deutch formulas yield the most reliable and consistent results. An interpretation of these results and a brief comparison with experiment are given.