Action absorption spectra of protonated a) pentacene, b) pentacenequinone, c) pentacenetetrone, d) anthraquinone, and e) phenan-threnequinone. The black lines are smoothing lines to guide the eye. The colored bars indicate calculated excited state transitions (S₀ → S_n) computed with the ωB97XD functional combined with three different basis sets. The height of the bars represent the oscillator strengths. The black vertical bars are the calculated excitation energies redshifted in energy by 0.5 eV for pentacenequinone (b), 0.4 eV for pentacenetetrone (c), and 1.6 eV for phenanthrenequinone (e).