Electrostatic spectrum and dielectric constant of nonpolar hard sphere fluids

We study the dielectric constant of a system of hard spheres with polarizable point dipoles at their center. The deviations from the Clausius–Mossotti formula are found at six volume fractions by computer simulation on a system with periodic boundary conditions. We also find the spectral density in the Stieltjes representation of the dielectric constant. This is directly related to the corresponding spectral density of a two-phase composite. The spectral density also characterizes the response of the system when the dipoles are modeled as Lorentz harmonic oscillators. The detailed structure of the spectrum, which we find by computer simulation, provides a severe test for theory.