Coupling of the rotational and translational degrees of freedom in molecular DIET: A classical trajectory study

Abstract

Classical trajectories have been calculated to address recent observations in laser-induced desorption of molecules: in particular that the mean translational energy increases with rotational energy of the desorbed molecule. A model is discussed which explains rotational excitation on the basis of an anisotropic repulsive interaction in the excited state. The observed correlation is a consequence of the lifetime spread in the excited state resulting in the fact that for those molecules quenched later more potential energy is transferred into translational and rotational energy. Calculated rotational state and velocity distributions are in semiquantitative agreement with experimental findings.