A methodology combining the polarizable continuum model and optimally-tuned range-separated (RS) hybrid functional was proposed for the quantitative characterization of the excited-state properties in oligoacene (from anthracene to hexacene) crystals. We show that it provides lowest vertical singlet and triplet excitation energies, singlet-triplet gap, and exciton binding energies in very good agreement with the available experimental data. We further find that it significantly outperforms its non-tuned RS counterpart and the widely used B3LYP functional, and even many-body perturbation theory within the GW approximation (based on a PBE starting point). Hence, this approach provides an easily applicable and computationally efficient tool to study the excited-state properties of organic solids of complexity. © 2017 Wiley Periodicals, Inc.
Keywords: exciton binding energy; oligoacene; singlet fission; singlet-triplet gap; time dependent density functional theory.
© 2017 Wiley Periodicals, Inc.