Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconducting incommensurate host-guest phases in compressed elemental
  sulfur   We use Density Functional Theory (DFT) and structure searching methods to
show that the ground state of elemental sulfur is a Barium-IVa type
incommensurate host-guest (HG) phase between $386$-$679$ GPa, becoming the
first group-VI element predicted to possess such a structure. Within the HG
phase, sulfur undergoes a series of transitions in which adjacent guest chains
are not aligned but rather offset by different amounts, which can be described
as a rearrangement of the stacking order of the chains. We show that these
chain rearrangements are intimately coupled to modulations of the host and
guest atoms which prove crucial to stabilising the HG structure. Unlike the
high-pressure HG phases of other elements, sulfur does not exhibit interstitial
charge localisation, and instead features strongly localised `voids' that are
depleted of electronic charge. Prior to adopting the HG structure, we predict
that sulfur possesses an orthorhombic structure of $Fdd2$ symmetry. We
calculate the superconducting critical temperatures of these newly discovered
phases, and show that $T_c$ is expected to peak between $24.8$ and $28.2$ K at
$271$ GPa.

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The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs