In this equation, the first term represents the bare Coulomb coupling between transition densities, and the second term represents the environment-mediated contribution; ρ i 0a (ρ j 0b ) is the 0 → a (0 → b) transition density of chromophore i (j), and µ ind l [ρ j 0b ] is the dipole induced on the MM atom l by the transition density ρ j 0b . All calculations were performed with a locally modified version of Gaussian 16 with an efficient QM/MMPol implementation .