First-Principle Calculations of the Band Shapes of Singlet–Triplet Transitions

Kubo’s generating function approach has been employed for simulating from first principles the spectral band shapes of singlet−triplet transitions of some aromatic compounds, representative for their rigid structures and aromatic characters of those used in solid-state optoelectronic devices. That approach yields Franck−Condon weighted densities of states in excellent agreement with experimental results, opening the way for reliable calculations of the rates of nonradiative singlet−triplet transitions, an important step for the in silico optimization of the molecular structure of dyes for solar energy conversion cells and for light-emitting diodes.