Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ${\it Ab \: initio}$ density-functional studies of 13-atom Cu and Ag
  clusters   The putative ground-state structures of 13-atom Cu and Ag clusters have been
studied using ${\it ab \: initio}$ molecular-dynamics (AIMD) simulations based
on the density-functional theory (DFT). An ensemble of low-energy
configurations, collected along the AIMD trajectory and optimized to nearest
local minimum-energy configurations, were studied. An analysis of the results
indicates the existence of low-symmetric bilayer structures as strong
candidates for the putative ground-state structure of Cu$_{13}$ and Ag$_{13}$
clusters. These bilayer structures are markedly different from a buckled
bi-planar (BBP) configuration and energetically favorable, by about 0.4$-$0.5
eV, than the latter proposed earlier by others. Our study reveals that the
structure of the resulting putative global-minimum configuration is essentially
independent of the nature of basis functions (i.e., plane waves versus
pseudoatomic orbitals) employed in the calculations, for a given
exchange-correlation functional. The structural configurations obtained from
plane-wave-based DFT calculations show a slightly tighter or dense first-shell
of Cu and Ag atoms than those from local-basis functions. A comparison of our
results with recent full-potential DFT simulations is presented.

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The categories of this paper are: math
29
The categories of this paper are: funct-an
8
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: cs
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
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The categories of this paper are: physics
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The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph