Modified generalized valence-bond method: A simple correction for the electron correlation missing in generalized valence-bond wave functions; Prediction of double-well states for Cr2 and Mo2

A new method for wave functions especially suited to studies of transition-metal systems is proposed and applied to H₂, N₂, Cr₂, and Mo₂, where it provides accurate bond energies and bond distances. The resulting potential curve for ground-state Cr₂ has a double well, and experiments to detect this unusual feature are suggested. The Mo₂ studies lead to an assignment for the long-lived emitter observed in matrix studies (it is the δδ^{* 3}Σ⁺_u state).