Internal state dependence of HCl/Ar(111) desorption rates

摘要

The rate of desorption of HCl from an Ar(111) surface as a function of the internal state of the physisorbed molecule is studied via a quasiclassical trajectory simulation of the system dynamics. Results from these calculations indicate that the desorption rate passes through a maximum at an initial rotational quantum number of 6, with the maximum rate being enhanced but the rate behavior not being altered qualitatively when a quantum of vibrational energy is added to the molecule. This observed rate dependence may be understood in terms of a transition of the system between distinct dynamical regimes that occurs as the rotational energy of the molecule is increased. Surface of section plots analogous to those used in the study of intramolecular energy transfer are found to provide a convenient means for identifying a transition of this sort.