K-A-MIXING IN THE UNIMOLECULAR DISSOCIATION OF NO2 STUDIED BY CLASSICAL DYNAMICS CALCULATIONS

Coriolis and centrifugal vibration-rotation coupling in the unimolecul ar dissociation of ground electronic state NO, has been examined by us ing classical trajectories. The time evolution of the projection K-a o f the rotational angular momentum N in a body-fixed frame is analyzed. The main result is a relation between the decomposition lifetime and the degree of K-a-mixing. For example, less than 30% of the available K-a space becomes populated for an average lifetime of 5 ps. This is c onsistent with the conclusions, based on time-resolved experiments, th at rotation-vibration transfer is slower than reaction except just abo ve the threshold. (C) 1998 Elsevier Science B.V.