A review is made of the status of computational analysis of the
Electric Field Gradient induced birefringence (EFGB) in atoms and
molecules. EFGB experiments are a standard means to determine
molecular electric quadrupole moments, or, if coupled to
measurement of the magnetic field induced birefringence
(Cotton-Mouton effect), to obtain estimates of magnetizability
anisotropies. Two existing semiclassical theories of the effect
lead to different numerical results for the physical observable,
i.e. the anisotropy of the refractive index. We discuss the
results obtained within these two formulations for rare gas atoms,
non-dipolar and dipolar small linear molecules employing Coupled
Cluster and Coupled Cluster Response theory, a state-of-the-art
method developed in the last decade and which currently
constitutes one of the most accurate tools available to determine
optical properties.
