Molecular trapping in the dissociation dynamics of N2 on W(110)

The dissociation of N-2 on the W(1 1 0) surface has been modelled using classical molecular dynamics on a potential energy surface obtained from density functional calculations. Although dissociation in this system is generally held to be direct and activated, we find that molecular trapping before dissociation is predominant up to the highest energy considered (1.5 eV). Nevertheless, the dissociation probability is an increasing function of molecular translational energy (typical of direct. activated dissociation) because access to the molecular trapping state is itself activated. (C) 2004 Elsevier B.V. All rights reserved.