PHOTODISSOCIATION OF HBR LIF(001) - A QUANTUM-MECHANICAL MODEL/

The photodissociation dynamics of HBr adsorbed on a LiF(001) surface i s studied using time-independent quantum mechanics. The photodissociat ion line shape and the Br(P1/2)-P-2/(BrP1/2)-P-2 yield ratio are compu ted and compared with the corresponding quantities for gas phase photo dissociation. The angular distribution of the hydrogen photofragments following excitation of adsorbed HBr is computed and found to agree qu alitatively with experimental data [Bourdon and co-workers, J. Chem. P hys. 95, 1361 (1991)]. The effect of polarization of the photon is ill ustrated and discussed. We find the field polarization to affect signi ficantly the magnitude of the photodissociation signal but not the ang ular dependence of the photofragment distribution, in agreement with e xperiment and in accord with expectations for a strongly aligned adsor bed phase.