Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: GW{\Gamma} + Bethe-Salpeter equation approach for photoabsorption
  spectra: Importance of self-consistent GW{\Gamma} calculations in small
  atomic systems   The self-consistent GW{\Gamma} method satisfies the Ward-Takahashi identity
(i.e., the gauge invariance or the local charge continuity) for arbitrary
energy ($\omega$) and momentum ($\bf q$) transfers. Its self-consistent
first-principles treatment of the vertex $\Gamma=\Gamma_v$ or $\Gamma_W$ is
possible to first order in the bare ($v$) or dynamically-screened ($W$) Coulomb
interaction. It is developed within a linearized scheme and combined with the
Bethe-Salpeter equation (BSE) to accurately calculate photoabsorption spectra
(PAS) and photoemission (or inverse photoemission) spectra (PES)
simultaneously. The method greatly improves the PAS of Na, Na$_3$, B$_2$, and
C$_2$H$_2$ calculated using the standard one-shot $G_0W_0$ + BSE method that
results in significantly redshifted PAS by 0.8-3.1 eV, although the PES are
well reproduced already in $G_0W_0$.

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The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph