Electronic Structure of Vanadium Cluster Anions : Measurement and DV-Xα Calculation of Photoelectron Spectra

Photoelectron spectra of vanadium cluster anions, V^-_n(3≤n≤100), were measured at the photon energy of 3.49 eV by using a magnetic-bottle-type photoelectron spectrometer. A spin-polarized DV-Xα method was adopted to calculate electronic structures of V^-_4 with several possible geometric structures. These calculated spectra were compared with that obtained by the experiment to examine a geometric structure and magnetic properties of V^-_4. It is revealed that V^-_4 is spin-polarized and has ferromagnetic spin coupling. Size-dependent change in electronic affinities of V^-_4 is explained in terms of a spherical conducting droplet model