Computer study of a classical quadrupole solid

Abstract

The Monte Carlo method is applied to a system of 32 classical free rotors on a face‐centered cubic lattice with toroidal boundary conditions. The particles interact via nearest‐neighbor electric quadrupole interactions, characterized by an energy Γ=6Q²/25R⁵. A first‐order phase transition is found at about k_BT=11Γ. Results are given for energy, specific heat, correlations of the form ${\mathrm{<\; Y}}_2^m\mathrm{\hspace{0.17em}(}\mathbf{k}{\mathrm{)*\hspace{0.17em}Y}}_2^n\mathrm{\hspace{0.17em}(}\mathbf{k}\mathrm{)\; >}$ , and various other quantities. Suggestions are made for further experimental and theoretical studies.