The calculation of self-energy corrections to the electron bands of a metal requires the evaluation of the intraband contribution to the polarizability in the small-q limit. When neglected, as in standard GW codes for semiconductors and insulators, a spurious gap opens at the Fermi energy. Systematic methods to include intraband contributions to the polarizability exist, but require a computationally intensive Fermi-surface integration. We propose a numerically cheap and stable method based on a fit of the power expansion of the polarizability in the small-q region. We test it on the homogeneous electron gas and on real metals such as sodium and aluminum.
Ab initio self-energy corrections in systems with metallic screening / M. Cazzaniga, N. Manini, L.G. Molinari, G. Onida. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 77:3(2008), pp. 035117.035117-1-035117.035117-6.
Titolo: | Ab initio self-energy corrections in systems with metallic screening |
Autori: | CAZZANIGA, MARCO (Primo) MANINI, NICOLA (Secondo) MOLINARI, LUCA GUIDO (Penultimo) ONIDA, GIOVANNI (Ultimo) |
Parole Chiave: | electron band ; metallic screening ; dielectric function |
Settore Scientifico Disciplinare: | Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici Settore FIS/03 - Fisica della Materia |
Data di pubblicazione: | 2008 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevB.77.035117 |
Appare nelle tipologie: | 01 - Articolo su periodico |