Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nuclear and Magnetic Structures of the Frustrated Quantum
  Antiferromagnet Barlowite, Cu$_{4}$(OH)$_{6}$FBr   Barlowite, Cu$_{4}$(OH)$_{6}$FBr, has attracted much attention as the parent
compound of a new series of quantum spin liquid candidates,
Zn$_{x}$Cu$_{4-x}$(OH)$_{6}$FBr. While it is known to undergo a magnetic phase
transition to a long-range ordered state at $T_{N} = 15$ K, there is still no
consensus over either its nuclear or magnetic structures. Here, we use
comprehensive powder neutron diffraction studies on deuterated samples of
barlowite to demonstrate that the only space group consistent with the observed
nuclear and magnetic diffraction at low-temperatures is the orthorhombic $Pnma$
space group. We furthermore conclude that the magnetic intensity at $T < T_{N}$
is correctly described by the $Pn^\prime m^\prime a$ magnetic space group,
which crucially allows the ferromagnetic component observed in previous
single-crystal and powder magnetisation measurements. As such, the magnetic
structure of barlowite resembles that of the related material clinoatacamite,
Cu$_{4}$(OH)$_{6}$Cl$_{2}$, the parent compound of the well-known quantum spin
liquid candidate hebertsmithite, ZnCu$_{3}$(OH)$_{6}$Cl$_{2}$.

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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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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: econ
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ph