The electric-field-gradient-induced birefringence of helium, neon, argon, and SF6

The results of an investigation of the electric-field-gradient-induced bire fringence of the noble gases He, Ne, Ar and of the octahedral system SF6 ar e presented. For all these systems the induced anisotropy of the refractive index is related to the sole temperature-independent contribution b(omega) , a combination of quadratic response functions. These hyperpolarizabilitie s, as well as their dispersion coefficients to seventh order, are calculate d at the optical experimental frequency by the CCSD response approach. The dispersion coefficients are used to determine the curve of b(omega) in the normal dispersion region. We show that for atoms the dipole-dipole-quadrupo le and the dipole-dipole-magnetic dipole contributions to the dispersion co efficients of b(omega) have intimate relations to the Cauchy moments and to the dispersion coefficients for the Verdet and the Cotton-Mouton constants . (C) 1999 American Institute of Physics. [S0021-9606(99)30441-4].