Molecular electric properties and nuclear and vibrational relaxation

Abstract
The effects of nuclear relaxation and change in vibrational molecular energy are accounted for in the theoretical determination of the molecular properties of HF, CH4, and C2H4. A method based on a finite-difference technique is employed. An analysis of the influence of these contributions versus the purely electronic contribution is made, together with an appraisal of the effect of vibrational excitation.