Figure 1.

Narrow-band blue TADF emitter, DABNA. (a) Chemical structure with an illustration of the multiple-resonance effect (HOMO/LUMO in red/blue). (b) Hole/particle wave functions shown in red/blue, as represented by the natural transition orbitals from ω*B97X calculations. (c) Difference density plot upon S₀–S₁ excitation calculated at the SCS-ADC(2) level where the decreased/increased electron density is shown in red/blue. Notice that the transition densities include correlation effects from double excitation terms and appear somewhat differently from b.