A STATIONARY STATE APPROACH TO RADIATIONLESS TRANSITIONS: RADIATION BANDWIDTH EFFECT ON EXCITATION PROCESSES IN POLYATOMIC MOLECULES

Abstract

Excitation processes associated with photon absorption by a molecule are considered in terms of the stationary states of the molecule and the bandwidth of the incident radiation. The conditions of validity of the usual interpretation that transitions occur to excited Born-Oppenheimer states followed by radiationless transitions to other B-O states are examined in terms of the various correlation and relaxation times of the system. In contrast to the usual case, for sufficiently narrow radiation bandwidths, it is demonstrated that excitation should be regarded as occuring to molecular stationary states.