Simple eigenvalue-self-consistent $$\overline{Δ}GW_0$$

Journal Article · 01 November 2018 · Journal of Chemical Physics

DOI: https://doi.org/10.1063/1.5042785 · OSTI ID:1571120

Vlček, Vojtěch ^[1]; Baer, Roi ^[2]; Rabani, Eran ^[3]; Neuhauser, Daniel ^[1]

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1. Univ. of California, Los Angeles, CA (United States)
2. Hewbrew Univ. of Jerusalem (Israel)
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tel Aviv Univ. (Israel)

We show that a rigid scissors-like GW self-consistency approach, labeled here $$\overline{Δ}GW_0$$, can be trivially implemented at zero additional cost for large scale one-shot $$G_0W_0$$ calculations. The method significantly improves one-shot $$G_0W_0$$ and for large systems is very accurate. $$\overline{Δ}GW_0$$ is similar in spirit to ev$$GW_0$$ where the self-consistency is only applied on the eigenvalues entering Green's function, while both W and the eigenvectors of Green's function are held fixed. $$\overline{Δ}GW_0$$ further assumes that the shift of the eigenvalues is rigid scissors-like so that all occupied states are shifted by the same amount and analogously for all the unoccupied states. We show that this results in a trivial modification of the time-dependent $$G_0W_0$$ self-energy, enabling an a posteriori self-consistency cycle. The method is applicable for our recent stochastic-$GW$ approach, thereby enabling self-consistent calculations for giant systems with thousands of electrons. The accuracy of $$\overline{Δ}GW_0$$ increases with the system size. For molecules, it is up to 0.4-0.5 eV away from coupled-cluster single double triple (CCSD(T)), but for tetracene and hexacene, it matches the ionization energies from both CCSD(T) and ev$$GW_0$$ to better than 0.05 eV. For solids, as exemplified here by periodic supercells of semiconductors and insulators with 6192 valence electrons, the method matches ev$$GW_0$$ quite well and both methods are in good agreement with the experiment.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences & Engineering Division (SC-22.2)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1571120
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 17 Vol. 149; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY