MOLECULES INTERACTING WITH SHORT, INTENSE LASER-PULSES - THE DYNAMICAL ROLE OF QUASI-STATIONARY STATES

A theoretical framework for the description of the pulse-induced react ion dynamics of molecules interacting with short, intense laser pulses is derived. Born-Oppenheimer adiabaticity is formulated in terms of q uasistationary Floquet states; its violation and the structure of the potential mixing electronic levels, and thus effecting this violation, is discussed; it is shown that, on the basis of quasistationary state s, this potential is (to a very good approximation) nonvanishing only around near degeneracies in the quasienergy spectrum where it has a si mple two-level structure. Ab initio calculations showing the effectivi ty of this scheme are performed for the H-2 molecule. Particular empha sis is put on bond-softening reactions; a new mechanism is described. (C) 1996 American Institute of Physics.