Abstract
Spin electronic states of wurtzite GaN nanostructres were studied by using ab initio molecular orbital calculations. Two models of pyramidal GaN clusters were constructed with the cluster axes parallel to the crystallographic c axis in the wurtzite. The atom at the apex of the cluster is nitrogen or gallium. We computed the lowest energy spin electronic states, spin densities, static electric fields, highest occupied molecular orbitals, and lowest unoccupied molecular orbitals for both clusters. The spin multiplicities of the clusters were found to be 13 and 3, depending on whether the atom at the apex was nitrogen or gallium, respectively. The GaN clusters were spontaneously spin-polarized in the lowest-energy states. Highly spin-polarized states were induced by the unpaired electrons on the surfaces of the nanostructures.
