Radiationless transitions in isolated molecules

Abstract

The radiationless decay rate constant of a single vibronic state and the equilibrium average nonradiative decay rate constant of an isolated molecule have been shown to be obtainable from the appropriate inverse Laplace transforms of the thermal average rate constants. An expression of the nonradiative decay rate constant of a single vibronic state, including the frequency changes, has been derived and has been compared with that obtained by Nitzan and Jortner and with that obtained by Heller et al. The microcanonical average rate constant has been shown to be to be derivable from the thermal rate constant by replacing β[β = (kT)−1] in the thermal rate constant by the corresponding β* of the isolated system, which is to be determined from the energy of the system.