Graphical Abstract: The ground state was calculated to be a quintet, which means a ferromagnetic interaction between centers. The
orbitals participating in exchange interaction according to ROHF+CI calculations are two molecular orbitals consisting of vanadium d-orbitals and two molecular orbitals with main contributions from p-orbitals of bipyridine ligands perpendicular to V-V axis, vanadium d- and p-orbitals and μ-oxygen p-orbital. Calculated energy values of the multielectronic states are placed in accordance with Lande rule. The value of magnetic moment at 293K calculated for the complex in vacuum taking into consideration the Boltzmann distribution and the energies of the excited states is 3.95BM which is in accordance with experimental value of 3.99BM (for complex in acetone).