Local Spin-Density Description of Multiple Metal-Metal Bonding:Mo2andCr2

Bonding and dissociation properties of multiply bonded ${\mathrm{Mo}}_2$ and ${\mathrm{Cr}}_2$ molecules are examined with use of the local spin-density theory and ab initio pseudopotentials. The equilibrium properties are in good agreement with experimental data. The core-polarization shifts are large; pseudopotentials give accurate results for multiply bonded systems only if outer-core $p$ electrons are included in the calculations. The results confirm the applicability of pseudopotential techniques to these systems.