Composition dependent properties of GaAs clusters Original Research Article

We used a combination of first principles electronic structure calculation and semi-empirical methods to study the composition dependence of physical properties of small and medium sized GaAs clusters. Structures and physical properties of Ga10−nAsn (n=0,1,2,…,10) clusters were determined using the ab initio Hartree–Fock method, with the STO-3G basis set. It was found that the structures of these clusters strongly depend on the composition and generally As-rich clusters are more stable than Ga-rich clusters. The dipole moment, HOMO-LUMO gap, vertical ionization energy, vertical electron affinity also depend on composition of the clusters and show an even/odd alteration with the number of Ga atoms (or As atoms) in the cluster.