Mf. Herman, MODEL-CALCULATIONS OF RESONANT VIBRATION TO VIBRATION TRANSITION-PROBABILITIES IN CLUSTERS, The Journal of chemical physics, 109(12), 1998, pp. 4726-4733
Results are presented for the calculated probability for resonant tran
sfer of vibrational excitation energy in clusters of identical molecul
es. The calculations are performed for two-dimensional clusters in ord
er to allow for calculations on larger clusters. Clusters of 5, 10, an
d 20 molecules are considered. The probability of resonant transfer is
calculated by quantum mechanically propagating the wave function for
the vibrational degrees of freedom of the molecules in the cluster, wh
ile the rotational and translational degrees of freedom evolve along c
lassical trajectories. The transition probabilities are averaged over
a canonical distribution of initial phase space points for the traject
ories. If the probability for the transition of a vibrational quantum
of energy from one molecule to some other molecule in an N molecule cl
uster is evaluated as N-1 independent two molecule vibrational problem
s, the results are found to be in excellent agreement with those obtai
ned from the propagation of the full N molecule vibrational problem. T
he results also show that quantum coherence effects result in an early
time nonlinear behavior in the transition probabilities that persists
for several picoseconds in these systems. (C) 1998 American Institute
of Physics.