Both classical and quasiclassical trajectories are used to study the dissoc
iation of noble gas dimers and the transitions between stable and metastabl
e dimers induced by collisions with noble gas atoms. Thermal reaction rates
are reported for these processes over a 0.3-3.5 range of reduced temperatu
res, T* = (k(B)T)/epsilon. Classical and quasiclassical data are compared t
o assess the importance of quantum effects in the reaction dynamics. (C) 19
99 American Institute of Physics. [S0021-9606(99)01207- 6].