Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical response of silver clusters and their hollow shells from
  Linear-Response TDDFT   We present a study of the optical response of compact and hollow icosahedral
clusters containing up to 868 silver atoms by means of time-dependent density
functional theory. We have studied the dependence on size and morphology of
both the sharp plasmonic resonance at 3-4 eV (originated mainly from
$sp$-electrons), and the less studied broader feature appearing in the 6-7 eV
range (interband transitions). An analysis of the effect of structural
relaxations, as well as the choice of exchange correlation functional (local
density versus generalized gradient approximations) both in the ground state
and optical response calculations is also presented. We have further analysed
the role of the different atom layers (surface versus inner layers) and the
different orbital symmetries on the absorption cross-section for energies up to
8 eV. We have also studied the dependence on the number of atom layers in
hollow structures. Shells formed by a single layer of atoms show a pronounced
red shift of the main plasmon resonances that, however, rapidly converge to
those of the compact structures as the number of layers is increased. The
methods used to obtain these results are also carefully discussed. Our
methodology is based on the use of localized basis (atomic orbitals, and
atom-centered- and dominant- product functions), which bring several
computational advantages related to their relatively small size and the
sparsity of the resulting matrices. Furthermore, the use of basis sets of
atomic orbitals also brings the possibility to extend some of the standard
population analysis tools (e.g., Mulliken population analysis) to the realm of
optical excitations. Some examples of these analyses are described in the
present work.

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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: 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-bio
21
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: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci