Electronic structure of vanadium cluster anions - Measurement and DV-X alpha calculation of photoelectron spectra

Photoelectron spectra of vanadium cluster anions, V-n(-)(3 less than or equal to n less than or equal to 100), were measured at the photon energy of 3.49 eV by using a magnetic-bottle-type photoelectron spectrometer. A spin-polarized DV-X alpha 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-n(-) is explained in terms of a spherical conducting droplet model.