Nonadiabatic effects in a method that combines classical and quantum mechanics

We have included nonadiabatic effects in the calculation of the dynamical evolution of a system where a quantum particle in a double well is coupled to a classical oscillator. By performing an exponential resummation of the evolution operator we have included ''polarization'' effects (similar to the self-energy corrections for an electron that moves in a polarizable medium) which lead to a renormalization of the energy of the quantum particle. (C) 1996 American Institute of Physics.