D-TO-S BONDING IN GAN

The interaction scheme for cubic GaN is constructed from the FP-LAPW d ensity of states and scalar relativistic free-atom LDA eigenvalues. Or bital interactions responsible for the DOS distribution, indicated by interaction lines, show that, due to the Ga d-to-N s bonding the d sta tes split into three subbands, displaying ds bonding, nonbonding, and antibonding properties. While nonbonding bands comprise d states of bo th t(2g) and e(g) symmetry components, bonding and antibonding ds stat es originate exclusively from the t(2g)-to-s orbital interactions. Due to the slight N p admixture, the relatively narrow band of nonbonding d states shows reversed tetrahedral t(2g)-e(g), splitting similar to that of fully occupied d states in II-VI semiconductors.