Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy levels, radiative rates and electron impact excitation rates for
  transitions in C III   We report energy levels, radiative rates (A-values) and lifetimes for the
astrophysically-important Be-like ion C III. For the calculations, 166 levels
belonging to the $n \le$ 5 configurations are considered and the {\sc grasp}
(General-purpose Relativistic Atomic Structure Package) is adopted. Einstein
A-coefficients are provided for all E1, E2, M1 and M2 transitions, while
lifetimes are compared with available measurements as well as theoretical
results, and no large discrepancies noted. Our energy levels are assessed to be
accurate to better than 1\% for a majority of levels, and A-values to better
than 20\% for most transitions. Collision strengths are also calculated, for
which the Dirac Atomic R-matrix Code ({\sc darc}) is used. A wide energy range,
up to 21 Ryd, is considered and resonances resolved in a fine energy mesh in
the thresholds region. The collision strengths are subsequently averaged over a
Maxwellian velocity distribution to determine effective collision strengths up
to a temperature of 8.0$\times$10$^5$ K, sufficient for most astrophysical
applications. Our data are compared with the recent $R$-matrix calculations of
Fern{\'a}ndez-Menchero, Del Zanna \& Badnell [A\&A 566 (2014) A104], and
significant differences (up to over an order of magnitude) are noted for
several transitions over the complete temperature range of the results.

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The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
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The categories of this paper are: cs
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The categories of this paper are: math
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The categories of this paper are: q-bio
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: cond-mat