Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Configuration interaction study of single and double dipole plasmon
  excitations in Na_8   We carry out a microscopic analysis of the ground and excited states of the
Na_8 metal cluster within the jellium model. We perform a series of
configuration interaction calculations on a Hartree-Fock basis and construct
eigenstates of the Hamiltonian which carry up to 4-particle 4-hole components.
Based on the analysis of the dipole transition strengths, we single out those
states which can be interpreted as the collective dipole plasmon and its double
excitations. These modes are found to possess a high degree of harmonicity,
deviations from the harmonic limit remaining, however, of the order of 10%.

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The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin