Analogous to the exciton intermediate state, Ψ Ex 𝐾𝐾 can be obtained from NOCI in WFT and NOSI in MSDFT. In principle, TDDFT and an MCSCF method could be used in both exciton and super-exchange steps, but it can be rather complicated with nonorthogonal orbitals between different fragment blocks. This is easily accomplished in MSDFT employing NOSI. Orbital delocalization. So far, the wave functions (or Kohn-Sham determinants) for the intermediate states have been constructed on the basis of fragmental BLMOs. Although incorporation of the SE effects introduces charge delocalization, the charge density is generally not sufficiently relaxed. Furthermore, the intermediate states decomposed at this point may have not included all configurational state functions used to determine the energies of the adiabatic excimer complex (𝑋𝑋𝑌𝑌) * . Therefore, in the final step of the MS-EDA method, we release the monomeric block-localization constraints and use the fully delocalized molecular orbitals to obtain the energies of the excited states for the excimer complex. These states are denoted as Ψ (𝑋𝑋𝑌𝑌) * 𝐾𝐾 without the dot "•" separating monomers X and Y. The energy change in this step is called orbital and configuration-state delocalization (OCD) energy, analogous to, but different from the CT energy term in ground-state EDA models since additional configurational state functions may also be included in the final step.