DYNAMICS OF A WAVEPACKET IN A SYSTEM OF CROSSING ELECTRONIC TERMS OF DIATOMIC-MOLECULES

Specific features of the behavior of IBr, a good example of diatomic m olecules, are inferred from quasiclassical expressions governing the d ynamics of a wavepacket in the predissociated electronic state. Multic hannel motion of a wavepacket in the system of crossing electronic ter ms tends to increase the number of fractions, into which the wavepacke t splits, and changes the qualitative pattern of the intramolecular dy namics, whenever there is a region of strong nonadiabaticity. It is sh own that the long-term evolution of the wavepacket furnishes informati on about the structure of both adiabatic and diabatic terms.