ROTATIONAL-TRANSLATIONAL CORRELATIONS IN PHOTOCHEMICALLY DESORBED MOLECULES

A simple dynamical model is presented that quantitatively explains the positive correlation between rotational and translational energies ch aracteristic of photodesorbed molecules. The model unifies two previou sly presented models for rotational and translational excitation mecha nisms, both of which exploit the fact that electronic excitation lifet imes are extremely short in most photodesorption processes from metal and semiconductor surfaces. Observed positive rotational-translational correlations are explained to be a consequence of the distribution of excited state residence times.