Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Salient Signature of van der Waals Interactions   van der Waals interactions govern the physics of a plethora of molecular
structures. It is well known that the leading term in the distance-based London
expansion of the van der Waals energy for atomic and molecular dimers decays as
$1/R^6$, where $R$ is the dimer distance. Using perturbation theory, we find
the leading term in the distance-based expansion of the intracule pair density
at the interatomic distance. Our results unveil a universal $1/R^3$ decay,
which is less prone to numerical errors than the $1/R^6$ dependency, and it is
confirmed numerically in H$_2$ and He$_2$ molecules. This \textit{signature} of
van der Waals interactions can be directly used in the construction of
approximate pair density and energy functionals including vdW corrections.

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The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: atom-ph
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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg