Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Efficient treatment of local meta-generalized gradient density
  functionals via auxiliary density expansion: the density fitting (DF) J+X
  approximation   We report an efficient technique to treat density functionals of the
meta-generalized gradient approximation (mGGA) class in conjunction with
density fitting of Coulomb terms (DF-J) and exchange-correlation terms (DF-X).
While the kinetic energy density $\tau$ cannot be computed in the context of a
DF-JX calculation, we show that the Laplacian of the density $\upsilon$ can be
computed with almost no extra cost. With this technique, $\upsilon$-form mGGAs
become only slightly more expensive (10%--20%) than GGAs in DF-JX
treatment---and several times faster than regular $\tau$-based mGGA
calculations with DF-J and regular treatment of the density functional. We
investigate the translation of $\upsilon$-form mGGAs into $\tau$-form mGGAs by
employing a kinetic energy functional, but find this insufficiently reliable at
this moment. However, $\upsilon$ and $\tau$ are believed to carry essentially
equivalent information beyond $\rho$ and $\Vert\vec\nabla\rho\Vert$ [Phys. Rev.
B 2007, 75, 155109], so a reparametrization of accurate mGGAs from the
$\tau$-form into the $\upsilon$-form should be possible. Once such functionals
become available, we expect the presented technique to become a powerful tool
in the computation of reaction paths, intermediates, and transition states of
medium sized molecules.

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The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: cs
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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph