Study on the Structure and Property of the Neutral GaxPy (x+y=8) and Anionic Gallium Phosphide Clusters Using DFT

Structure, electronic state, and energy of semiconductor binary micro-clusters, GaxPy and GaxPy−, having eight atoms have been computed using density functional theory (DFT) method. Structural optimization and frequency analysis are performed at the B3LYP/6-311+G(2df) level. The charge-induced structural changes of these anions have been discussed. The strong Ga-P bond is favored over the P-P bond in GaxPy− (x+y=8), in comparison with the corresponding neutral cluster. The calculations predict the existence of previously unknown isomers (i.e. Ga1P7−, Ga2P6−, Ga3P5−, Ga6P2−, and Ga7P1−). Among different GaxPy and GaxPy− (x+y=8) clusters, Ga4P4 and Ga4P4− are more stable. Two types of energy separations are reported in this study, adiabatic electron affinities (ΔEAEA) and vertical detachment energies (ΔEVDE), wherever applicable, and are compared with those described in other published data in the literature. Adiabatic electron affinities for Ga4P4 and Ga5P3 are in good agreement with those obtained in the experiments. Mulliken population analyses indicate that the bonding in GaP clusters is of a mixed type.