Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Distortion-Dependent Raman Spectra and Mode Mixing in RMnO3 Perovskites   The polarized Raman spectra of orthorhombic RMnO3 series
(R=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Y) were studied at room temperature. The
variation of phonon frequencies with R ionic radius rR as a whole confirms the
commonly accepted Raman line assignments with two noticeable exceptions: (1)
with decreasing rR the stretching Ag(1) and bending Ag(3) modes strongly mix
for R=Sm to Tb, while for further decrease or rR (R=Dy,Ho,Y) the Ag(3) mode is
observed at higher frequency than Ag(1) mode; (2) similar distortion-dependent
mode mixing takes place for the rotational Ag(2) and O1(x) [Ag(7)] modes. The
mode mixing is particularly strong for the RMnO3 compounds with rR values close
to the transition from A-type to incommensurate sinusoidal antiferromagnetic
ordering at low temperatures. The frequency of rotational Ag(2) and Ag(4) modes
scales to the angles of MnO6 [101] and [010] rotations, respectively, and could
be used as a measure of their value.

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The categories of this paper are: comp-gas
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: math
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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: q-alg
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The categories of this paper are: physics
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The categories of this paper are: funct-an