| Autor: |
Dauth, Matthias, Caruso, Fabio, Kümmel, Stephan, Rinke, Patrick |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Phys. Rev. B 93, 121115 (2016) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.93.121115 |
| Popis: |
We identify the deviation from the straight line error (DSLE) -- i.e., the spurious non-linearity of the total energy as a function of fractional particle number -- as the main source for the discrepancy between experimental vertical ionization energies and theoretical quasiparticle energies, as obtained from the $GW$ and $GW$+SOSEX approximations to many-body perturbation theory (MBPT). For self-consistent calculations, we show that $GW$ suffers from a small DSLE. Conversely, for perturbative $G_0W_0$ and $G_0W_0$+SOSEX calculations the DSLE depends on the starting point. We exploit this starting-point dependence to reduce (or completely eliminate) the DSLE. We find that the agreement with experiment increases as the DSLE reduces. DSLE-minimized schemes, thus, emerge as promising avenues for future developments in MBPT. |
| Databáze: |
arXiv |
| Externí odkaz: |
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