Mechanism of efficient V-V in collisions of N-2(+) (nu > 0) with N-2

Fully quantum mechanical calculations of state-to-state cross sections in v ibrationally deactivating collisions of N-2(+)(nu > 0) with N-2 are reporte d. A study of the opacity function confirms that V-V is a longer range proc ess than V-T, as previously inferred from experiments, but only marginally so. Variations in the transition probability are found to be of greater imp ortance in determining the state-to-state cross sections. Multi-quantum V-V , while weaker than single-quantum V-V, is competitive with single-quantum V-T processes. (C) 1999 Elsevier Science B.V. All rights reserved.