TREATMENT OF NONADIABATIC TRANSITIONS BY DENSITY-MATRIX EVOLUTION ANDMOLECULAR-DYNAMICS SIMULATIONS

A density matrix evolution (DME) method (H.J.C. Berendsen and J. Mavri , J. Phys. Chem., 97 (1993) 13469) to simulate the dynamics of quantum systems embedded in a classical environment is presented. The DME met hod allows treatment of nonadiabatic transitions. As numerical example s the collinear collision of a noble gas atom with a quantum oscillato r, a quantum oscillator in a noble gas bath, and proton tunnelling in an intramolecular hydrogen bond in aqueous solution are presented.