Benchmarking the Starting Points of the GW Approximation for Molecules

The GW approximation is nowadays being used to obtain accurate quasiparticle energies of atoms and molecules. In practice, the GW approximation is generally evaluated perturbatively, based on a prior self-consistent calculation within a simpler approximation. The final result thus depends on the cho...

Full description

Saved in:
Bibliographic Details
Published inJournal of chemical theory and computation Vol. 9; no. 1; pp. 324 - 329
Main Authors Bruneval, Fabien, Marques, Miguel A. L
Format Journal Article
LanguageEnglish
Published United States American Chemical Society 08.01.2013
Subjects
Chemical Sciences
Engineering Sciences
Physics
Online AccessGet full text

Cover

More Information
Summary:The GW approximation is nowadays being used to obtain accurate quasiparticle energies of atoms and molecules. In practice, the GW approximation is generally evaluated perturbatively, based on a prior self-consistent calculation within a simpler approximation. The final result thus depends on the choice of the self-consistent mean-field chosen as a starting point. Using a recently developed GW code based on Gaussian basis functions, we benchmark a wide range of starting points for perturbative GW, including Hartree–Fock, LDA, PBE, PBE0, B3LYP, HSE06, BH&HLYP, CAM-B3LYP, and tuned CAM-B3LYP. In the evaluation of the ionization energy, the hybrid functionals are clearly superior results starting points when compared to Hartree–Fock, to LDA, or to the semilocal approximations. Furthermore, among the hybrid functionals, the ones with the highest proportion of exact-exchange usually perform best. Finally, the reliability of the frozen-core approximation, that allows for a considerable speed-up of the calculations, is demonstrated.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1549-9618
1549-9626
DOI:10.1021/ct300835h