Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How van der Waals interactions determine the unique properties of water   While the interactions between water molecules are dominated by strongly
directional hydrogen bonds (HBs), it was recently proposed that relatively
weak, isotropic van der Waals (vdW) forces are essential for understanding the
properties of liquid water and ice. This insight was derived from ab initio
computer simulations, which provide an unbiased description of water at the
atomic level and yield information on the underlying molecular forces. However,
the high computational cost of such simulations prevents the systematic
investigation of the influence of vdW forces on the thermodynamic anomalies of
water. Here we develop efficient ab initio-quality neural network potentials
and use them to demonstrate that vdW interactions are crucial for the formation
of water's density maximum and its negative volume of melting. Both phenomena
can be explained by the flexibility of the HB network, which is the result of a
delicate balance of weak vdW forces, causing e.g. a pronounced expansion of the
second solvation shell upon cooling that induces the density maximum.

29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph