Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum mechanical motion of off-center ion in external magnetic field   We consider the magnetostatic response to an external magnetic field of a
crystal containing off-center ions, such as Li^+ in KCl and KBr or the apical
oxygens O(A) in the LaSCO family of layered perovskites. Magnetic dipoles are
deduced from the matrix elements of the energy operator of a spinning particle
in a magnetic field which particle also satisfies the nonlinear Mathieu
equation. The magnetic moments are found to increase in magnitude as the system
goes from the lowest energy ground state to the higher lying excited states.
Our conclusions are in concert with earlier studies of magnetic dipoles from
circular currents based on Ampere's theorem.

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The categories of this paper are: cs
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: math
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The categories of this paper are: funct-an