**Necessity of capillary modes in a minimal model of nanoscale hydrophobic
solvation**

S Vaikuntanathan and G Rotskoff and A Hudson and PL Geissler, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 113, E2224-E2230 (2016).

DOI: 10.1073/pnas.1513659113

Modern theories of the hydrophobic effect highlight its dependence on
length scale, emphasizing the importance of interfaces in the vicinity
of sizable hydrophobes. We recently showed that a faithful treatment of
such nanoscale interfaces requires careful attention to the statistics
of capillary waves, with significant quantitative implications for the
calculation of solvation thermodynamics. Here, we show that a coarse-
grained lattice model like that of Chandler **Chandler D (2005) Nature
437(7059):640-647**, when informed by this understanding, can capture a
broad range of hydrophobic behaviors with striking accuracy.
Specifically, we calculate probability distributions for microscopic
density fluctuations that agree very well with results of atomistic
simulations, even many SDs from the mean and even for probe volumes in
highly heterogeneous environments. This accuracy is achieved without
adjustment of free parameters, because the model is fully specified by
well-known properties of liquid water. As examples of its utility, we
compute the free-energy profile for a solute crossing the air-water
interface, as well as the thermodynamic cost of evacuating the space
between extended nanoscale surfaces. These calculations suggest that a
highly reduced model for aqueous solvation can enable efficient
multiscale modeling of spatial organization driven by hydrophobic and
interfacial forces.

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