Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometrical and electronic structures of tripotassium-doped hydrocarbon
  superconductors: Density functional calculations   A systemically theoretical study has been presented to explored the crystal
structures and electronic characteristics of polycyclic aromatic hydrocarbons
(PAHs), such as solid phenanthrene, picene, 1,2;8,9-dibenzopentacene, and
7-phenacenes, since these PAHs exhibited the superconductivity when potassium
doping into. For tripotassium-doped phenanthrene and picene, we demonstrate the
K atomic positions to fit the experimental lattice parameters, and analyze the
distinction between the stablest configuration and the fitted experimental one.
Based on the first-principles calculations, for the first time, we predict the
possible crystal configurations of pristine and tripotassium-doped
1,2;8,9-dibenzopentacene and 7-phenacenes, respectively. For these four PAHs,
the electronic structures after doping are investigated in details. The results
show that the electronic characters near the Fermi level are high sensitive to
structure. Because of the change of the benzene rings arrangement, the
1,2;8,9-dibenzopentacene exhibits visibly different band structures from other
three PAHs. In these metallic PAHs, two bands cross the Fermi level which
results in the complicated multiband feature of Fermi surfaces. Fascinatingly,
we find that the electronic states of potassium contribute to the Fermi
surfaces especially for K-3$d$ electrons, which improves a way to understand
this superconductivity. As a result, we suggest that the rigid-band picture is
invalidated due to the hybridization between K atoms and PAH molecules as well
as the rearrangement and distortion of PAH molecules.

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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
2
The categories of this paper are: math
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The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: solv-int