From the molecular quadrupole moment of oxygen to the macroscopic quadrupolarizability of its liquid phase

Abstract

Liquid oxygen is an example for a quadrupolar medium—a dense fluid made of nonpolar molecules carrying a significant quadrupolar moment. In this work, we present a method for the computation of the macroscopic quadrupolarizability of such a quadrupolar liquid. As a first step, the quadrupole moment and the molecular quadrupolarizability of O2 are calculated from first principles. Next, we apply a model generalizing Onsager’s dielectric cavity theory to compute the macroscopic quadrupolarizability of liquid oxygen under a wide range of conditions. Literature data for the density and dielectric permittivity of oxygen are used to determine the cavity size independently.