Self-energy calculation of the hydrogen atom: Importance of the unbound states

Abstract

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Numerically Precise Benchmark of Many-Body Self-Energies on Spherical Atoms

“…Notably, the rationale for the SOSEX diagram as a cure for the self-screening problem of GW seems now justified if H is considered. This confirms early observations that the GW self-screening problem in H can be exacerbated by a starting point that suffers from a self-interaction/delocalization error and is instead small when an accurate starting point is adopted. , …”

“…This confirms early observations that the GW self-screening problem in H can be exacerbated by a starting point that suffers from a self-interaction/delocalization error and is instead small when an accurate starting point is adopted. 50 , 51 …”

“…This confirms early observations that the GW self-screening problem in H can be exacerbated by a starting point that suffers from a self-interaction/delocalization error and is instead small when an accurate starting point is adopted. 50,51 Going from the PBE to the PBE0 starting point greatly affects the performance of GW, which is now comparable with GW+SOSEX@PBE and scarcely the one of GW+SOSEX. On the one hand, this confirms a reduced starting point dependence of the GW+SOSEX self-energy, 27,28 also seen in self-consistent schemes.…”

“…Moreover, assuming a negligible contribution from relativistic effects, the numerical precision we achieve allows for a direct comparison with experiments. To our knowledge, in the literature there are few MBPT studies focused on atoms, ,,− while some general MBPT benchmarks include atomic systems as a part of larger test sets. , …”

Ground state properties of 3d metals from self-consistent GW approach

“…This problem was already documented in atomic calculations. For example, Sakuma and Aryasetiawan [39] have shown that in order to get the convergent total energy of the hydrogen atom (the simplest one!) in the GW approx imation, one has to sum up not only over bound states but also over an infinite number of the continuum states.…”