$GW$ vertex corrected calculations for molecular systems

Emanuele Maggio; Georg Kresse

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arXiv · 1706.01815

$GW$ vertex corrected calculations for molecular systems

Emanuele Maggio·Georg Kresse

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Abstract

Hedin's scheme is solved with the inclusion of the vertex function ($GW\Gamma$) for a set of small molecules. The computational scheme allows for the consistent inclusion of the vertex both at the polarizability level and in the self-energy. A diagrammatic analysis shows that the self-energy formed with this four-point vertex does not lead to double counting of diagrams, that can be classified as direct "bubbles" and exchange diagrams. By removing the exchange diagrams from the self-energy, a simpler approximation is obtained, called $GW^{\rm{tc-tc}}$. Very good agreement with expensive wavefunction-based methods is obtained for both approximations.

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Emanuele Maggio, Georg Kresse. 2017-06-06. $GW$ vertex corrected calculations for molecular systems. https://arxiv.org/abs/1706.01815

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