NONLINEAR QUANTUM EFFECTS ON ELECTRON-TRANSFER REACTIONS

To study nuclear quantum effects on electron transfer reactions, the n on-adiabatic rate constant is expanded in terms of Planck's constant. The expansion to the second order reproduces well the quantum correcti on in the activation free energy for a quantum Monte Carlo simulation of water. In addition, the spin-boson model is discussed using the exp ansion. The validity of the rate constant given by the spin-boson mode l is investigated in non-linear systems. Conditions for obtaining exac t values of the rate constant are established in the second order of P lanck's constant. In liquids, the conditions are satisfied if the one- body distribution function does not change during the electron transfe r reaction. (C) 1997 Elsevier Science S.A.