Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recovery of harmonic-like behaviour of the polar mode in BaTiO$_3$ at
  high pressure   The local structure of high pressure BaTiO$_3$ has been interrogated by
neutron total scattering methods, up to pressures of 4.18 GPa at ambient
temperature. Competitive refinements of cubic, tetragonal and rhombohedral
distortion modes against pair distribution functions indicate contrasting local
structure behaviour of temperature- and pressure-induced cubic BaTiO$_3$.
Suppression of the mode amplitude, isotropy of the order parameter direction
and loss of sensitivity to correlated Ti displacements at high pressure all
suggest a high-pressure local structure that is more consistent with the
harmonic approximation, rather than an order-disorder model which better
describes high-temperature cubic BaTiO$_3$ in the vicinity of the tetragonal
phase transition.

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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: q-alg
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The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org