The structure of triniobium dinitride from zero electron kinetic energy photoelectron spectroscopy and density functional calculations

Zero electron kinetic energy photoelectron spectra are reported for Nb3N2. The geometry of the cluster was determined by comparing the experiments with density functional and Franck-Condon factor calculations, Both the neutral and cation have a three dimensional C-2v symmetry with each of the two nitrogen bridging two niobium atoms of the metal isosceles triangle. The symmetric deformation of niobium vibrations in the ion has a frequency of 257 cm(-1). The asymmetric niobium stretching of the ion is 17 cm(-1) larger than that of the neutral. Bonding between niobium and nitrogen is stronger in the ion than in the neutral. (C) 1997 Elsevier Science B.V.