Scheme 1. Thermodynamic Cycle Relating the Energy Components in Multistate Energy Decomposition Analysis of Exciplex Binding Energy ΔE_b.

The top row corresponds to the physical process of exciplex formation (eq 2). The remaining illustration highlights the energy terms defined by eq 4. The shapes of objects represent molecular geometries, while different colors depict the polarized wave functions under different conditions. Blocks with boundaries denote fragment-localized wave functions, all of which can be variationally optimized. The lower panels in light-yellow shade specify the minimal active space (MAS) in nonorthogonal state interacion (NOSI) calculations, respectively, for the exciton state, derived from local excited states (Lex) shown in pink, and for the super-exchange (SE) contribution due to charge transfer diabatic states. Adapted with modifications from ref (5). Copyright 2023 American Chemical Society.