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 He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV   We report calculations of energy levels, radiative rates and electron impact
excitation cross sections and rates for transitions in He-like Ga XXX, Ge XXXI,
As XXXII, Se XXXIII and Br XXXIV. The {\sc grasp} (general-purpose relativistic
atomic structure package) is adopted for calculating energy levels and
radiative rates. For determining the collision strengths, and subsequently the
excitation rates, the Dirac Atomic R-matrix Code ({\sc darc}) is used.
Oscillator strengths, radiative rates and line strengths are reported for all
E1, E2, M1 and M2 transitions among the lowest 49 levels of each ion.
Additionally, theoretical lifetimes are provided for all 49 levels of the above
five ions. Collision strengths are averaged over a Maxwellian velocity
distribution and the effective collision strengths obtained listed over a wide
temperature range up to 10$^{8}$ K. Comparisons are made with similar data
obtained using the Flexible Atomic Code ({\sc fac}) to highlight the importance
of resonances, included in calculations with {\sc darc}, in the determination
of effective collision strengths. Discrepancies between the collision strengths
from {\sc darc} and {\sc fac}, particularly for some forbidden transitions, are
also discussed. Finally, discrepancies between the present results for
effective collision strengths with the {\sc darc} code and earlier
semi-relativistic $R$-matrix data are noted over a wide range of electron
temperatures for many transitions in all ions.

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The categories of this paper are: nucl-ex
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The categories of this paper are: q-alg
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas