TWO-DIMENSIONAL WAVE PACKET STUDIES OF PHOTON-STIMULATED DESORPTION OF NO FROM A METAL SURFACE INDUCED BY SINGLE AND MULTIPLE ELECTRONIC EXCITATIONS

摘要

The photon-stimulated desorption dynamics of nitric oxide (NO) from the Pt(lll) surface is investigated using time-dependent quantum mechanics. Empirical potential energy surfaces with two degrees of freedom (desorption and NO vibration) are employed for both the neutral and anionic states. The influence of the time delay between transitions is investigated for desorption with single and double excitation/deexcitation cycles. An improved Monte Carlo Sampling scheme is proposed for processes undergoing multiple excitations. For desorption involving a single excitation, the calculated vibrational and kinetic energy distributions of the desorbed NO agree very well with experimental observations. When desorption is driven by multiple excitations, higher vibrational excitation is found for NO. (C) 1997 American Institute of Physics. [References: 54]