Investigation of electric-field-gradient-induced birefringence in H2 and D2

An ab initio computational investigation of
the electric–field–gradient–induced birefringence in H2
and D2 is presented. The quadrupole moment and all
linear and non-linear optical properties contributing to
the induced anisotropy of the refractive index are computed
by means of Coupled Cluster Singles and Doubles
response theory. The latter leads for these systems
to Full Configuration Interaction results. Vibrational
averaging, centrifugal distortion due to rotation, isotope
effects and differences between ortho and para species
are also considered.