Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First-principles computational study of defect clustering in solid
  solutions of ThO$_{2}$ with trivalent oxides   The energetics of mixing and defect ordering in solid solutions of
fluorite-structured ThO$_{2}$ with oxides of trivalent cations (Sc, In, Y, Nd,
La) are investigated by electronic density-functional-theory (DFT). Through DFT
calculations of structures enumerated by lattice-algebra techniques, we
identify the lowest-energy patterns for defect clustering for four separate
dopant concentrations. The most stable structures are characterized by a
repulsive interaction between nearest-neighbor vacancies on the oxygen
sublattice. The enthalpies of formation with respect to constituent oxides are
positive for all dopants considered, and show a tendency to decrease in
magnitude as the size and electronegativity of the trivalent dopant decrease.
Due to the small positive formation enthalpies and low oxygen-vacancy binding
energy with La dopants, La$_{2}$O$_{3}$-ThO$_{2}$ solid solutions are predicted
to have relatively high ionic conductivities relative to those for the other
aliovalent dopants considered. Our results are compared with those for the more
widely studied ZrO$_{2}$ and CeO$_{2}$ fluorite-structured solid solutions with
trivalent cations.

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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
29
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: comp-gas