title: Understanding surface photochemistry from first principles: the case of CO-NiO(100).
abstract: The excitation mechanism in the CO-NiO(100) system induced by a uv-laser pulse has been investigated from first principles. For the laser-driven process, the relevant electronically excited states are identified, and it is shown that a transition within the CO molecule is the crucial excitation step rather than substrate mediated processes. A new mechanism is proposed, in which the formation of a genuine C-Ni bond in the excited state is the driving force for photodesorption rather than electrostatic interactions, as has been found in similar systems. This results in very high velocities of CO molecules desorbing from the NiO(100) surface after electronic relaxation.
authors.affiliation: Institut für Reine und Angewandte Chemie, Carl von Ossietzky Universität Oldenburg, Postfach 2503, D-26111 Oldenburg, Germany.
authors.forename: Imed
authors.initials: I
authors.lastname: Mehdaoui
authors.forename: Thorsten
authors.initials: T
authors.lastname: Klüner