Dissociation energy ofMo2andMo2+

Using local-spin-density theory and fully relativistic outer-core–valence-electron pseudopotentials we calculate the dissociation energy, bond length, and vibrational frequency of ${\mathrm{Mo}}_2$ and ${\mathrm{Mo}}_2^{+}$. The results for ${\mathrm{Mo}}_2$ are in good agreement with experiment and we predict a higher vibrational frequency, shorter bond length, and 20% greater dissociation energy upon ionization. A discussion of ‘‘bonding orbitals’’ which reduce the dissociation energy is given.