Evaluation of it GW approximations for the self-energy of a Hubbard cluster

C. Verdozzi, R.W. Godby, S. Holloway

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We evaluate several approximations for the self-energy operator and dielectric function of systems of interacting electrons using a two-dimensional Hubbard cluster for which the self-energy, dielectric function, and one-particle Green's function may be calculated exactly. The results show the GW approximation (in the form in which it is commonly used in ab initio calculations for real materials) to be relatively successful in establishing the main features of the spectrum, even when the electron-electron interaction is not weak. It is also clear that improving the G andW used in this approximation without including vertex corrections in the self-energy does not lead to major improvements.
Original languageEnglish
Pages (from-to)2327-2330
Number of pages3
JournalPhysical Review Letters
Issue number12
Publication statusPublished - 20 Mar 1995

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© 1995 American Physical Society.

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