Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetostructural effects and phase transition in Cr_2O_3 under pressure   We have successfully calculated the electronic and structural properties of
chromia (Cr_2O_3) in the Local Spin Density Approximation (LSDA). We predict a
transformation from the corundum to the Rh_2O_3(II) structure around 15 GPa in
the anti-ferromagnetic (AFM) phase as well as in the paramagnetic (PM)
insulating state which occurs above the Neel temperature (T_N). This transition
is relevant to interpreting the optical anomalies observed in the absorption
spectrum of ruby under pressure. We have modeled the structural properties of
the PM state using a Landau-like expansion of the magnetostriction energy. This
treatment correctly describes the structural anomalies across T_N in the
corundum phase and indicates that the AFM and PM insulating states should have
distinct compressive behaviors.

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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg