Generalized treatment of the quadrupole-quadrupole interaction of low symmetry molecules and its effect on the second dielectric virial coefficient

Abstract

The experimental dielectric virial coefficient data of ethylene as determined by Bose and Cole are reanalyzed. The quadrupole‐quadrupole interaction energy of low symmetry molecules is calculated, and its effect on the second dielectric virial coefficient is determined by a Monte Carlo numerical integration. It is shown that taking into account the quadrupole‐quadrupole interaction does not appreciably change the quadrupole moment value of ethylene. By combining the experimental results of dielectric and induced birefringence measurements, the quadrupole moment components of a low symmetry molecule can be estimated. The experimentally derived quadrupole moment components of ethylene, Θ_zz = 2.0 × 10⁻²⁶ esu·cm² and Θ_xx = 2.09 × 10⁻²⁶ esu·cm² and the existing theoretical values agree reasonably well.