Classical approximation to nonradiative electronic relaxation in condensedphase systems

We present a study of the classical limit of nonradiative electronic relaxa tion in condensed phase systems. The discrete Hamiltonian representing an i mpurity in a condensed phase environment is mapped onto a continuous form u sing the Meyer-Miller approach. The classical electronic relaxation rate is obtained within the framework of the reactive flux formalism and is compar ed 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 ra te than the mixed quantum-classical treatment. We provide a time domain ana lysis of the results.