Nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties by means of electrical property expansions: Application to HF, CH4, CF4, and SF6

摘要: Electrical property derivative expressions are presented for the nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties. For CF4 SF6, as opposed HF CH4, a term that is quadratic in vibrational anharmonicity (and not previously evaluated any molecule) makes an important second hyperpolarizability of SF6. A comparison between calculated experimental values difference (anisotropic) Kerr effect electric field induced second-harmonic generation shows that, at Hartree–Fock level, relaxation/infinite approximation gives correct trend (in series CF4, SF6) but order 50% too small.