Vibrational effects on electric and magnetic susceptibilities: application to the properties of the water molecule

We present perturbation theory expressions for the pure vibrational contributions to the hypermagnetizability. These expressions are complete to second order in perturbation theory and include contributions from third derivatives of the properties and the quartic force constants. We calculate zero-point vibrational and pure vibrational effects on the polarizability, magnetizability and hypermagnetizability of the water molecule, and discuss the effects of nuclear motion on the Cotton-Mouton constant of water in the gas phase. This is the first investigation of vibrational effects on the hypermagnetizability of a polyatomic molecule.