A new adiabatic approach to the photodissociation of polyatomic molecules

Abstract

An adiabatic theory of polyatomic photodissociation is developed that explicitly treats the interaction between the relative and internal motion and leads to an expression for the nuclear wavefunction of the final dissociative state which differs considerably from the zeroth-order distorted-wave approximation. The vibrational frequencies ..omega../sub i/ of the fragments are found to depend on the interfragment distance. In the evaluation of the matrix element needed to describe the energy distribution of the fragments, it is found necessary to use values of ..omega../sub i/ different from the frequencies of the free fragments. These values of ..omega../sub i/ can be expressed in terms of the force constants of the precursor system. Inverse vibrational distributions are obtained from this theory in accord with recent experimental data.