Fig. 2: Theoretical calculations.
From: Tunable afterglow for mechanical self-monitoring 3D printing structures
Natural transition orbitals (NTOs) describing the excitation characters of the S1, T1 and T3 states and vertical excitation energy levels with spin–orbit coupling matrix elements (ξ) calculated at the optimized molecular geometries in gas phase at the B3LYP/6-311 G(d) level of (a) DTPPAO and (b) tBuDTPPAO; the weights of the hole-electron contributions to the excitations are included.
