Geometry and electronic structure of Vn(Bz)m complexes.

First-principles calculations based on the generalized gradient approximation to the density functional theory are performed to explore the global geometries, ground-state spin multiplicities, relative stabilities, and energetics of neutral and anionic V(n)(Bz)(m) (n=1-3, m=1-4, with n<m) complexes. The calculated results show that the V(n)(benzene)(m) complexes clearly prefer sandwich structures to rice-ball structures. The ground-state spin multiplicities of the V(n)(benzene)(n+1) complexes increased linearly with the size of the system (i.e., n). In the anionic complexes, the V(benzene)(2) complex is found to be unstable against the autodetachment of the extra electron. The energy difference between adiabatic and vertical electron affinities is found to be very less, indicating negligible ionization-induced structural changes in the ground-state geometries of V(n)(benzene)(n+1) complexes.