Reconstruction of the (110) surface of III-V semiconductor compounds

We have used ab initio quantum chemical methods to determine the structure of the clean (110) surface of the nine III-V compounds with III = B, Al or Ga, and V = N, P or As. The theoretical results for small clusters give geometries in good agreement with the experimental geometry for GaAs (the only case for which an experimental structure is available), supporting the use of such clusters in studying the reconstruction of the other systems. We find in all cases that the reconstruction of these (110) surfaces is determined by local valence hybridization forces on the surface atoms. To show the effects of these valence forces we have also carried out extensive calculations on the trihydrides of the above-mentioned elements, for which we have calculated bond distances, bond angles, and the variation of the total energy with bond angle, leading to inversion barriers for the trihydrides of column V elements.