Numerical MCSCF study of the total (electronic and nuclear) parallel polarizability and hyperpolarizability for the H₂, HD and D₂ molecules

Abstract

We present numerical MCSCF calculations of the electronic and nuclear components of the parallel molecular polarizabilities (α _zz ) and the second hyperpolarizabilities (γ _zzzz ) of H₂, HD and D₂. Contrary to the H⁺ ₂ case, where the vibrational contribution to γ is fifty times larger than the pure electronic γ, the vibrational γ and the electronic γ for H₂ have the same magnitude. The electronic correlation has a stronger effect on α and γ for vibrationally-excited states than for the ground state.