THEORETICAL-STUDY OF SMALL GALLIUM-ARSENIDE CLUSTERS

Electronic structures and stabilities of Ga(n)As(n) clusters (n = 1-3) are explored by means of accurate quantum-chemical calculations using ab initio effective core potentials (ECP). Our results on GaAs and Ga2As2 are in good agreement with the conclusions from previous studies on these systems. We find that Ga3As3 has a capped trigonal bipyramid ground-state structure, similar to those of Si6 and Al3P3. Several other local minima including planar and prismatic structures have also been found. Comparison with our previous results for AlP and MgS clusters indicates that the electronegativity difference between the constituents of a mixed cluster is a major factor in determining its bonding and geometrical properties.