Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometric, electronic properties and the thermodynamics of pure and
  Al--doped Li clusters   The first--principles density functional molecular dynamics simulations have
been carried out to investigate the geometric, the electronic, and the finite
temperature properties of pure Li clusters (Li$_{10}$, Li$_{12}$) and Al--doped
Li clusters (Li$_{10}$Al, Li$_{10}$Al$_2$). We find that addition of two Al
impurities in Li$_{10}$ results in a substantial structural change, while the
addition of one Al impurity causes a rearrangement of atoms. Introduction of
Al--impurities in Li$_{10}$ establishes a polar bond between Li and nearby Al
atom(s), leading to a multicentered bonding, which weakens the Li--Li metallic
bonds in the system. These weakened Li--Li bonds lead to a premelting feature
to occur at lower temperatures in Al--doped clusters. In Li$_{10}$Al$_2$, Al
atoms also form a weak covalent bond, resulting into their dimer like behavior.
This causes Al atoms not to `melt' till 800 K, in contrast to the Li atoms
which show a complete diffusive behavior above 400 K. Thus, although one Al
impurity in Li$_{10}$ cluster does not change its melting characteristics
significantly, two impurities results in `surface melting' of Li atoms whose
motions are confined around Al dimer.

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The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an