APPLICATION OF SCF-SI THEORY TO VIBRATIONAL MOTION IN POLYATOMIC-MOLECULES

The self-consistent field and state interaction methods are formulated for coupled vibrational motion in polyatomic molecules. This general approach should have many applications. Two model systems are considered. The vibration in nonbending CO2 is studied and the calculated energies are compared to those obtained by use of other approximate methods. A model isomerization reaction in which motion along the reaction coordinate is coupled to a harmonic bond is studied with the self-consistent field method. The dependence of the rate of isomerization on coupling strength and excitation in the harmonic bond is focused upon and easily understood within the self-consistent field framework. © 1979 American Chemical Society.