Non-adiabatic charge transfer process of oxygen on metal surfaces

The dynamics of charge transfer processes of oxygen on metal surfaces are investigated. The analysis is based on a set of diabatic potential energy surfaces, each representing a different charged oxygen species. Empirical universal potential energy functions have been constructed that mimic the oxygen-silver, oxygen-aluminum and oxygen-cesium systems. The differences between the work functions of these metals are reflected in the potential parameters. The dynamics are followed by solving the multichannel time-dependent Schrodinger equation starting from oxygen in the gas phase. Only the direct short time part of the dynamics is followed leading to the creation O-2(-) in the gas phase as well as dissociative chemisorption. A large portion of the wave function is trapped in molecular chemisorption charged states. It is found that the position of the crossing seam between potentials has a profound influence on the outcome. (C) 1999 Elsevier Science B.V. All rights reserved.