Density functional study of the second row transition metal dimers

Equilibrium geometries, vibrational frequencies and dissociation energies of the second row transition metal dimers (from Y2 to Cd2, except Tc2) were studied by use of density functional methods B3LYP, BLYP, B3PW91, BHLYP, BP86, B3P86, SVWN, MPW1PW91 and PBE1PBE. The accuracy of DFT methods is found to be highly dependent on the functional employed, in particular for vibrational frequency and dissociation energy. In most cases, the predicted bond distance is in general agreement with experiment and previous theoretical results. For van der Waals dimer Cd2, B3LYP and BLYP have excellent performance in predicting the bond distance. For Ag2, all density functional methods used in this study perform well in producing the bond distance, vibrational frequency and dissociation energy.