Interaction of Cl-2 molecules with GaAs(110) surface

We present ab-initio molecular dynamics calculations for the chemisorption of Cl on GaAs(110), to study the adsorption sites and the presentation of surface order at the early stages of adsorption. We simulated the impact of a single Cl-2 molecule on the surface using a (2 x 2) surface cell and the repeated slab geometry. Along the dynamical path dissociation occurs, bonds are created between Cl and the atoms of Ga and As and local quenching of the buckling relaxation is found. The dynamical results are compared with the optimization geometries obtained by allowing the two Cl atoms to adsorb on Ga and As. The adsorption on both sites is the most stable arrangement. Disorder effects are seen in the dynamics. (C) 1998 Elsevier Science B.V. All rights reserved.