Classical Approximation to Nonradiative Electronic Relaxation in Condensed Phase Systems

We present a study of the classical limit of nonradiative electronic relaxation in condensed phase systems. The discrete Hamiltonian representing an impurity in a condensed phase environment is mapped onto a continuous form using the Meyer−Miller approach. The classical electronic relaxation rate is obtained within the framework of the reactive flux formalism and is compared to the fully quantum mechanical result, and to a mixed quantum−classical approximation. Similar to the case of vibrational relaxation, we find that the fully classical treatment is closer to the fully quantum mechanical rate than the mixed quantum−classical treatment. We provide a time domain analysis of the results.