GaAs-based clusters

This paper presents the results of cluster calculations performed for selected Ga- and As-based clusters: These include the ${\mathrm{GaH}}_3$, ${\mathrm{AsH}}_3$, ${\mathrm{GaAsH}}_6$, and ${\mathrm{Ga}}_2$ ${\mathrm{As}}_2$ ${\mathrm{H}}_{10}$ model clusters. Ab initio calculations were performed within the restricted Hartree-Fock formalism. An effective core potential is adopted in order to limit these calculations to valence electrons. The total energies, equilibrium geometries, and harmonic vibrational frequencies are calculated for each of the model clusters. Binding energies for both the ${\mathrm{GaH}}_3$ and ${\mathrm{AsH}}_3$ model clusters are determined. Absorbances are calculated for all of the model clusters and are compared with experimental infrared-absorption data for hydrogen adsorption on GaAs(100) surfaces.