A DENSITY FUNCTIONAL STUDY OF SMALL NIOBIUM CLUSTERS

Geometrical structures of Nbn clusters up to n = 7 are calculated at the B3LYP/LanL2DZ level. The average binding energy, along the local magnetic moments, is calculated, together with the HOMO–LUMO gap and the mean bond length. The ground-state structures of niobium clusters favor higher-dimensional configuration and higher coordination number. The average binding energy increases with the number of atoms and the magnetic order into the clusters depends on the cluster size, all the clusters present a HOMO–LUMO gap larger than 1 eV.