Vibrational and thermal averaging of the indirect nuclear spin-spin coupling constants of CH4, SiH4, GeH4 and SnH4

Abstract

The effects of nuclear motion on the indirect nuclear spin-spin coupling constants of CH4, SiH4, GeH4 and SnH4 were calculated up to first order in the normal coordinates. We report the random-phase approximation, multiconfigurational linear response and second-order polarization propagator calculations of the zero-point rovibrational corrections, as well as the temperature dependence of both one-bond and two-bond coupling constants. We find that the random-phase approximation overestimates the zero-point corrections. The results demonstrate that rovibrational corrections are as important as the non-contact terms and must be included in accurate determinations of indirect nuclear spin-spin coupling constants of these molecules.