Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure-induced ferroelectric phase of LaMoN$_3$   Nitride perovskites are supposed to exhibit excellent properties as oxide
analogues and may even have better performance in specific fields for their
more covalent characters. However, till now, very limited nitride perovskites
have been reported. In this work, a nitride perovskite LaMoN$_3$ has been
systematically studied by first-principles calculations. The most interesting
physical property is its ferroelectric $R3c$ phase, which can be stabilized
under a moderate hydrostatic pressure ($\sim1.5$ GPa) and probably remain
meta-stable under the ambient condition. Its ferroelectric polarization is
considerable large, $80.3$ $\mu$C/cm$^2$, driven by the nominal $4d^0$ rule of
Mo$^{6+}$, and the covalent hybridization between Mo's $4d$ and N's $2p$
orbitals is very strong. Our calculation not only predicts a new ferroelectric
material with prominent properties, but also encourages more studies on
pressure engineering of functional nitrides.

6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg