The Electronic Structure of Transition Metal Clusters

Abstract

The investigations on metallic clusters increase day by day. Experimentalists as well as theorists are interested to know whether the small metallic clusters have similar properties to those of bulk metals. The review article on this field was first given by OZIN [1]. In this report, the electronic structure of Cu, Ni, and Zn clusters will be discussed. Using X_α-SCF method, MESSMER et al. C2] have shown that small transition metal clusters such as Cu₈ have a density of states (DOS) parallel to that of corresponding metals: the d band is embedded in the s band or the top of the d band and that of the s band consist of the Fermi level. On the other hand, using ab initio SCF calculations and resulting orbital energies, BASCH et al. [3] and BACHMANN et al. [4] have given completely different pictures: the d band is far from the the s band for Ni clusters [3] as well as Cu clusters [43. The difference between the two is schematically shown in Fig. 1. We, therefore, have determined to investigate the electronic structure of the transition metal clusters with the aid of the ab initio SCF and configuration interaction (CI) calculations. Whether the small transition metal clusters have the characteristics of the bulk or not is tested by

• 1) the position of the Fermi level

• 2) the position of the d band relative to the Fermi level

• 3) the s and d band widths, and

• 4) the magnitude of the electron affinity.