Figure 1.

Computed adiabatic ground-state energy profile for the diassociation of ${\mathrm{H}}_2^{+}$ using Hartree–Fock (HF) theory (black), density functional theory with the hybrid B3LYP functional (blue), and multireference valence bond-density functional theory (VBDFT) using the B3LYP functional with the aug-cc-pVTZ basis set (green) and with the aug-cc-pV6Z basis set (red). The diabatic energy profile for the degenerate block-localized electronic configuration Ψ([H⁺][H•]) computed using the BLDFT method is shown in brown, and the coupling energy V₁₂ is given in light blue, both using the aug-cc-pVTZ basis functions.