Polyhedral molecular orbital theory to niobium clusters and metal complex

Abstract

The polyhedral molecular orbital method was applied to several nioblum clusters, and a model of standard trigonometric integral was used in order to simplify the calculation of group overlap integrals. Furthermore, the results were checked by the density functional theory. The comparisons show that the polyhedral molecular orbital theory is a more efficient way for studying the bond characters of polyhedral compounds, especially transition metal clusters, than the traditional calculation methods. For example, this method predicts that the sizes of niobium clusters possess low magnetic moments as ground states, and the electronic structures of Nb-4 and [Nb6Cl12](+4). Although the geometry structures of Nb-4 and Nb-6 are transformed resulting from the Jahn-Teller effects and electronic-correlated effects, the theoretical prediction also show the trend of transformation.