Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Local order and orientational correlations in liquid and crystalline
  phases of carbon tetrabromide from neutron powder diffraction measurements   The liquid, plastic crystalline and ordered crystalline phases of CBr$_4$
were studied using neutron powder diffraction. The measured total scattering
differential cross-sections were modelled by Reverse Monte Carlo simulation
techniques (RMC++ and RMCPOW). Following successful simulations, the single
crystal diffraction pattern of the plastic phase, as well as partial radial
distribution functions and orientational correlations for all the three phases
have been calculated from the atomic coordinates ('particle configurations').
The single crystal pattern, calculated from a configuration that had been
obtained from modelling the powder pattern, shows identical behavior to the
recent single crystal data of Folmer et al. (Phys. Rev. {\bf B77}, 144205
(2008)). The BrBr partial radial distribution functions of the liquid and
plastic crystalline phases are almost the same, while CC correlations clearly
display long range ordering in the latter phase. Orientational correlations
also suggest strong similarities between liquid and plastic crystalline phases,
whereas the monoclinic phase behaves very differently. Orientations of the
molecules are distinct in the ordered phase, whereas in the plastic crystal
their distribution seems to be isotropic.

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The categories of this paper are: hep-lat
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The categories of this paper are: stat
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
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The categories of this paper are: q-bio