where the notation (𝑋𝑋 • 𝑌𝑌) separating monomers X and Y by the symbol "  " represents a block- localized bimolecular complex, and the parentheses indicate that the product wave function of the monomers (ground or excited states) is antisymmetrized, e.g., Ψ (𝑋𝑋•𝑌𝑌) = 𝐴𝐴 ̂{Ψ 𝑋𝑋 Ψ 𝑌𝑌 } . This convention is used throughout this Letter. We note that the molecular geometry used to determine