Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules III: A Benchmark of GW Methods

Joseph W Knight; Xiaopeng Wang; Lukas Gallandi; Olga Dolgounitcheva; Xinguo Ren; J Vincent Ortiz; Patrick Rinke; Thomas Körzdörfer; Noa Marom

doi:10.1021/acs.jctc.5b00871

Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules III: A Benchmark of GW Methods

J Chem Theory Comput. 2016 Feb 9;12(2):615-26. doi: 10.1021/acs.jctc.5b00871. Epub 2016 Jan 25.

Authors

Joseph W Knight¹, Xiaopeng Wang¹, Lukas Gallandi², Olga Dolgounitcheva³, Xinguo Ren⁴, J Vincent Ortiz³, Patrick Rinke⁵, Thomas Körzdörfer², Noa Marom¹

Affiliations

¹ Physics and Engineering Physics, Tulane University , New Orleans, Louisiana 70118, United States.
² Computational Chemistry, University of Potsdam , 14476 Potsdam, Germany.
³ Department of Chemistry and Biochemistry, Auburn University , Auburn, Alabama 36849-5312, United States.
⁴ Key Laboratory of Quantum Information, University of Science and Technology of China , Hefei, Anhui 230026, China.
⁵ COMP/Department of Applied Physics, Aalto University School of Science , P.O. Box 11100, FI-00076 Aalto, Finland.

PMID: 26731609
DOI: 10.1021/acs.jctc.5b00871

Abstract

The performance of different GW methods is assessed for a set of 24 organic acceptors. Errors are evaluated with respect to coupled cluster singles, doubles, and perturbative triples [CCSD(T)] reference data for the vertical ionization potentials (IPs) and electron affinities (EAs), extrapolated to the complete basis set limit. Additional comparisons are made to experimental data, where available. We consider fully self-consistent GW (scGW), partial self-consistency in the Green's function (scGW0), non-self-consistent G0W0 based on several mean-field starting points, and a "beyond GW" second-order screened exchange (SOSEX) correction to G0W0. We also describe the implementation of the self-consistent Coulomb hole with screened exchange method (COHSEX), which serves as one of the mean-field starting points. The best performers overall are G0W0+SOSEX and G0W0 based on an IP-tuned long-range corrected hybrid functional with the former being more accurate for EAs and the latter for IPs. Both provide a balanced treatment of localized vs delocalized states and valence spectra in good agreement with photoemission spectroscopy (PES) experiments.