Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear Electromagnetic Interactions in Energetic Materials   We study the scattering of electromagnetic waves in anisotropic energetic
materials. Nonlinear light-matter interactions in molecular crystals result in
frequency-conversion and polarization changes. Applied electromagnetic fields
of moderate intensity can induce these nonlinear effects without triggering
chemical decomposition, offering a mechanism for non-ionizing identification of
explosives. We use molecular dynamics simulations to compute such
two-dimensional Raman spectra in the terahertz range for planar slabs made of
PETN and ammonium nitrate. We discuss third-harmonic generation and
polarization-conversion processes in such materials. These observed far-field
spectral features of the reflected or transmitted light may serve as an
alternative tool for stand-off explosive detection.

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The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
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The categories of this paper are: stat
26
The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat