Bruneval F, Sottile F, Olevano V, Del Sole R, Reining L. Many-body perturbation theory using the density-functional concept: beyond the GW approximation.
PHYSICAL REVIEW LETTERS 2005;
94:186402. [PMID:
15904386 DOI:
10.1103/physrevlett.94.186402]
[Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Indexed: 05/02/2023]
Abstract
We propose an alternative formulation of many-body perturbation theory that uses the density-functional concept. Instead of the usual four-point integral equation for the polarizability, we obtain a two-point one, which leads to excellent optical absorption and energy-loss spectra. The corresponding three-point vertex function and self-energy are then simply calculated via an integration, for any level of approximation. Moreover, we show the direct impact of this formulation on the time-dependent density-functional theory. Numerical results for the band gap of bulk silicon and solid argon illustrate corrections beyond the GW approximation for the self-energy.
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