Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Mountaineering Strategy to Excited States: Highly-Accurate Energies
  and Benchmarks for Bicyclic Systems   Pursuing our efforts to define highly-accurate estimates of the relative
energies of excited states in organic molecules, we investigate, with
coupled-cluster methods including iterative triples (CC3 and CCSDT), the
vertical excitation energies of 10 bicyclic molecules (azulene, benzoxadiazole,
benzothiadiazole, diketopyrrolopyrrole, fuofuran, phthalazine, pyrrolopyrrole,
quinoxaline, tetrathiafulvalene, and thienothiophene). In total, we provide
\emph{aug}-cc-pVTZ reference vertical excitation energies for 91 excited states
of these relatively large systems. We use these reference values to benchmark
various wave function methods, i.e., CIS(D), EOM-MP2, CC2, CCSD, STEOM-CCSD,
CCSD(T)(a)*, CCSDR(3), CCSDT-3, ADC(2), ADC(2.5), ADC(3), as well as some
spin-scaled variants of both CC2 and ADC(2). These results are compared to
those obtained previously on smaller molecules. It turns out that while the
accuracy of some methods is almost unaffected by system size, e.g., CIS(D) and
CC3, the performance of others can significantly deteriorate as the systems
grow, e.g., EOM-MP2 and CCSD, whereas others, e.g., ADC(2) and CC2, become more
accurate for larger derivatives.

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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th