Photodesorption of NO from a metal surface: quantum dynamical implications of a two-mode model Original Research Article

Open-system density matrix theory is used to study the dissipative quantum dynamics of photoinduced, hot-electron mediated desorption of NO from Pt(111). Two electronic states are considered and both the DIET (Desorption Induced by Electronic Transitions) and DIMET (Desorption Induced by Multiple Electronic Transitions) limits addressed. Besides the center-of-mass motion of the molecule perpendicular to the surface plane, the vibrational motion of the NO molecule is accounted for. In a first, methodological part the interrelations between various “direct” and “jumping wave packet” methods to solve the underlying open-system Liouville-von Neumann equations of motion, are emphasized. In a second, applied part we investigate (i) the relevance of the popular “negative ion resonance” model, (ii) the role of coordinate-dependent electronic relaxation, and (iii) the implications of multiple-electronic excitations.