SURFACE HOPPING AND FULLY QUANTUM DYNAMICAL WAVEPACKET PROPAGATION ONMULTIPLE COUPLED ADIABATIC POTENTIAL SURFACES FOR PROTON-TRANSFER REACTIONS

A general method for fully quantum mechanical wavepacket propagation o n multiple adiabatic potential surfaces is developed, An analytical ex pression is derived for the second-derivative nonadiabatic coupling te rms that arise in the adiabatic representation. Both this fully quantu m mechanical wavepacket propagation method and the mixed quantum/class ical surface hopping method ''molecular dynamics with quantum transiti ons'' (MDQT) are applied to a one-dimensional two-state model system f or a proton transfer reaction. The remarkable agreement between the wa vepacket and the MDQT methods justifies the use of MDQT for simulation of proton transfer reactions in solution. (C) 1997 Elsevier Science B .V.