By applying computational methods to a Ga16As17H36 cluster, the behaviour of an As2 molecule which approached an As-terminated non-reconstructed GaAs(001) surface along the C2 symmetry axis of the cluster was studied. In order to describe the interaction between the As2 molecule and the cluster, the total energy of the system was calculated for various cluster-As2 distances. The results showed that the system (cluster plus molecule) possessed a stable conformation in which one As atom resided at a tetrahedral interstitial site within the crystal.

Model for the Incorporation of Excess Arsenic into Interstitial Positions during the Low-Temperature Growth of GaAs(001) Layers. T.Marek, S.Kunsági-Máté, H.P.Strunk: Journal of Applied Physics, 2001, 89[11], 6519-22