Predissociation in polyatomic molecules

Abstract

The complexity of polyatomic, as compared with diatomic, predissociation theory is attributed to the existence of more than one exit channel, or fragment internal excitation state. It is shown, for type I predissociation that both the relative populations of the exit channels and the spectroscopic line width may be expressed in terms of matrix elements of the appropriate interaction function between the initial vibrational and the final vibrational-translational wavefunctions. The general formulae obtained are applied to elucidate the effect of a conical intersection on the variation of the spectroscopic linewidth with the vibrational quantum numbers of the predissociating state.