Outer-valence Electron Spectra of Prototypical Aromatic Heterocycles from an Optimally Tuned Range-Separated Hybrid Functional.
Density functional theory with optimally tuned range-separated hybrid (OT-RSH) functionals has been recently suggested [Refaely-Abramson et al.Phys. Rev. Lett.2012,109, 226405] as a nonempirical approach to predict the outer-valence electronic structure of molecules with the same accuracy as many-body perturbation theory. Here, we provide a quantitative evaluation of the OT-RSH approach by examining its performance in predicting the outer-valence electron spectra of several prototypical gas-phase molecules, from aromatic rings (benzene, pyridine, and pyrimidine) to more complex organic systems (terpyrimidinethiol and copper phthalocyanine). For a range up to several electronvolts away from the frontier orbital energies, we find that the outer-valence electronic structure obtained from the OT-RSH method agrees very well (typically within ∼0.1-0.2 eV) with both experimental photoemission and theoretical many-body perturbation theory data in the GW approximation. In particular, we find that with new strategies for an optimal choice of the short-range fraction of Fock exchange, the OT-RSH approach offers a balanced description of localized and delocalized states. We discuss in detail the sole exception found-a high-symmetry orbital, particular to small aromatic rings, which is relatively deep inside the valence state manifold. Overall, the OT-RSH method is an accurate DFT-based method for outer-valence electronic structure prediction for such systems and is of essentially the same level of accuracy as contemporary GW approaches, at a reduced computational cost.
Institute of Solid State Physics, Graz University of Technology , 8010 Graz, Austria ; Department of Materials and Interfaces, Weizmann Institute of Science , Rehovoth 76100, Israel.
David A
DA
Egger
Department of Materials and Interfaces, Weizmann Institute of Science , Rehovoth 76100, Israel.
Shira
S
Weissman
Department of Materials and Interfaces, Weizmann Institute of Science , Rehovoth 76100, Israel.
Sivan
S
Refaely-Abramson
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Sahar
S
Sharifzadeh
Theoretical Physics IV, University of Bayreuth , 95440 Bayreuth, Germany.
Matthias
M
Dauth
Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, Hebrew University , 91904 Jerusalem, Israel.
Roi
R
Baer
Theoretical Physics IV, University of Bayreuth , 95440 Bayreuth, Germany.
Stephan
S
Kümmel
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States ; Department of Physics and Kavli Energy Nanosciences Institute, University of California , Berkeley, California 94720, United States.
Jeffrey B
JB
Neaton
Institute of Solid State Physics, Graz University of Technology , 8010 Graz, Austria.
Egbert
E
Zojer
Department of Materials and Interfaces, Weizmann Institute of Science , Rehovoth 76100, Israel.
Leeor
L
Kronik