Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bulk moduli of PbS$_{x}$Se$_{1-x}$, PbS$_{x}$Te$_{1-x}$ and
  PbSe$_{x}$Te$_{1-x}$ from a thermodynamical model compared to generalized
  gradient approximation approach   Very recently, first-principle technique of full-potential linearized
augmented plane-wave method, by using for exchange-correlation potential the
generalized gradient approximation (GGA), was employed for the study of the
lead chalcogenide semiconductors' alloys PbS$_{x}$Se$_{1-x}$,
PbS$_{x}$Te$_{1-x}$ and PbSe$_{x}$Te$_{1-x}$. These density functional
calculations led to the determination of structural, electronic and optical
properties, including the values of lattice constants and bulk moduli as a
function of composition. Here, we investigate the latter properties, but by
employing a thermodynamical model which has been suggested for the formation
and migration of defects in solids including several recent applications in
semiconductors. The following crucial difference emerges when comparing the
present results with those deduced by density functional calculations: Among
the alloys studied, GGA calculations identify that PbS$_{x}$Te$_{1-x}$ exhibits
the most evident non-linear variation of the bulk modulus versus the
composition, while according to the thermodynamical model such an evident
non-linear behavior -and maybe somewhat stronger- is also expected for
PbSe$_{x}$Te$_{1-x}$. A tentative origin of this diversity is discussed.

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The categories of this paper are: nlin
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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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: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci