MULTIPLE TRAVERSALS OF A CONICAL INTERSECTION - ELECTRONIC QUENCHING IN NA-ASTERISK-2(H)

The conical intersection in the collision of a Na(3p(2)P) atom with H- 2, occurs at large H-H distances, Time dependent quantal computations exhibit many sequential non-adiabatic couplings, each of which is loca lized in time, where the quenching probability per traversal is small. During the collision, the population of the ground state increases al most in a random walk fashion until the partners recede after many H-2 , vibrational periods. Changing the masses suggests that other systems can also exhibit such a snarled quenching process which cannot be des cribed as a single non-adiabatic event per collision.