Correlation between electronic and molecular structure distortions and vibrational properties. I. Adiabatic approximations

The perturbation theory was applied to study the distortions of the electronic and molecular structures of a polarizable molecule. The coupled differential equations for the vibrational wave functions were obtained with the help of adiabatic approximations. The effects of electrostatic potential on vibrational properties were discussed. The relationship between the vibrational frequency shift and molecular structural distortion was also discussed.