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arXiv · 0709.1564

Ab-initio self-energy corrections in systems with metallic screening

Marco Cazzaniga·Nicola Manini·Luca Guido Molinari·Giovanni Onida
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Abstract

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.

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Marco Cazzaniga, Nicola Manini, Luca Guido Molinari, Giovanni Onida. 2007-11-20. Ab-initio self-energy corrections in systems with metallic screening. https://doi.org/10.1103/physrevb.77.035117

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