Electrostatic spectrum of renormalized polarizability for nonpolar dielectric

The Drude–Lorentz model of a nonpolar dielectric with the simple cubic, face-centered and body-centered crystal lattice structures is considered. The electrostatic spectral density of the renormalized polarizability is found. The problem is equivalent to the calculation of the electronic density of states in the model. The obtained spectra are analyzed and the critical points are identified. The results are compared with the computer simulation data for a hard-sphere fluid. In the latter, the structure analogous to the transverse and longitudinal polarization modes characteristic for a solid dielectric is shown to exist.