QUANTUM STUDY OF ORIENTED NO SCATTERING FROM AG(111) - ORIENTATIONAL STEERING AND EFFECTS OF SURFACE CORRUGATION

We present quantum calculations of oriented NO scattering from a corru gated Ag(111) surface, based on the potential energy surfaces of DePri sto and Alexander [J. Chem. Phys. 94 (1991) 8454]. A time-resolved ana lysis of the NO-axis distribution reveals significant reorientation as the molecule reaches the repulsive wall of the interaction, even when normal energy is 3-4 times larger than the well depth. The incoming m olecule may be further focused onto highly-anisotropic impact spots be cause of translational steering near the surface. The fact that all mo lecules do not achieve the most stable configuration before striking t he surface causes the dynamical stereospecificity, that is, rotational excitation is enhanced when the O end rather than the N end, is direc ted towards Ag(111). Comparison with the rotationally-resolved steric measurements of Geuzebroek et al. [J. Phys. Chem. 95 (1991) 8409] is m ade. (C) 1998 Elsevier Science B.V. All rights reserved.