Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic isotope shift factors for the Cu $4s \; ^2S_{1/2} - 4p \;
  ^2P^o_{3/2}$ line   State-of-the-art relativistic multiconfiguration Dirac-Hartree-Fock
calculations have been performed to evaluate the electronic field and mass
isotope shift factors of the Cu~I resonance line at $\lambda = 324.8$~nm. A
linear correlation between the mass factors and the transition energy is found
for elaborate correlation models, allowing extrapolation to the observed
frequency limit. The relativistic corrections to the recoil operator reduces
the transition mass factor by 5~\%.

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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: comp-gas
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin