Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: van der Waals forces in density functional theory: The vdW-DF method   A density functional theory (DFT) that accounts for van der Waals (vdW)
interactions in condensed matter, materials physics, chemistry, and biology is
reviewed. The insights that led to the construction of the Rutgers-Chalmers van
der Waals Density Functional (vdW-DF) are presented with the aim of giving a
historical perspective, while also emphasising more recent efforts which have
sought to improve its accuracy. In addition to technical details, we discuss a
range of recent applications that illustrate the necessity of including
dispersion interactions in DFT. This review highlights the value of the vdW-DF
method as a general-purpose method, not only for dispersion bound systems, but
also in densely packed systems where these types of interactions are
traditionally thought to be negligible.

22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
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The categories of this paper are: nucl-th
2
The categories of this paper are: math
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga