SUPERCOLLISION EVENTS IN WEAK COLLISIONAL ENERGY-TRANSFER OF HIGHLY EXCITED SPECIES

The results are reported of a series of trajectory studies on Xe colliding with highly excited azulene, obtained using the method of Lim and Gilbert. These show a small fraction (about 1%) of supercollisions (ones which transfer an abnormally large amount of energy), in accord with results from several different experimental techniques. The trajectories show that these rare supercollisions occur when a hydrogen atom is compressed between the bath gas and part or all of the carbon framework. This produces a strong repulsion between the Xe and H as the relative coordinate is driven high up the repulsive wall, if vibrational phases, or rotation, of the substrate framework are such that the bath gas and substrate separate during this compression, the final energy transfer is large.