In order to explore the variations in the ESM D simulations of the two quantum chemical approaches, we initially examined the electronic energies and intrinsic features of the adiabatic states computed for the ground states of the isomers. In the case of 2-TP, a comparison of the results in Table suggests a reduction in the energy separation between the S 1 and T 1 states, from the TDDFT theory (≈ 0.92 eV) to CASSCF (≈ 0.55 eV). A similar reduction is observed for the S 1 /T 2 energy separation. These features, evident in the ground state, are maintained throughout the simulation, as illustrated in the dynamic energy profiles in For instance, in contrast to 2-TP, the stabilization effect is evident in 3-TP for both singlet and triplet states. It is particularly significant in the lower singlet and triplet states, thus facilitating a population decay to the ground state. In addition to the alterations in the state energies, a reorganization of the underlying features is also observed in the CASSCF computation of 3-TP. These modifications in the multiconfigurational model also render the S 1 /T 1 and S 1 /T 3 transition channels energetically accessible in 4-TP, leading to an enhanced triplet population in the corresponding dynamics.