# Simple Parameter-Free Bridge Functionals for Molecular Density Functional Theory. Application to Hydrophobic Solvation

3 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire
NIMBE UMR 3685 - Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M)
Abstract : Computer simulations have been substantial in understanding the fine details of hydrophobic solvation and hydrophobic interactions. Alternative approaches based on liquid-state theories have been proposed, but are not yet at the same degree of completeness and accuracy. In this vein, a classical, molecular density functional theory approach to hydrophobic solvation is introduced. The lowest, second-order approximation of the theory, equivalent to the hypernetted chain approximation in integral equations, fails in describing correctly cavitation free-energies. It is corrected here by two simple, angular-independent, so-called bridge functionals; they are parameter-free in the sense that all variables can be fixed unambiguously from the water bulk properties, including pressure, isothermal compressibility, and liquid-gas surface tension. A hard-sphere bridge functional, based on the known functional of a reference hard fluid system, turns out to face strong limitations for water. A simpler weighted density approximation is shown to properly reproduce the solvation free energy of hydrophobes of various sizes, from microscopic ones to the nanoscale, and predicting the solvation free-energy of a dataset of more than 600 model hydrophobic molecules having a variety of shapes and sizes with an accuracy of a quarter of $k_BT$ compared to Monte-Carlo simulations values. It constitutes an excellent starting point for a general functional describing accurately both hydrophobic and hydrophilic solvation, and making it possible to study non-idealized hydrophobic interactions.
Document type :
Journal articles
Domain :

https://hal-cea.archives-ouvertes.fr/cea-02899078
Contributor : Serge Palacin <>
Submitted on : Monday, November 30, 2020 - 4:19:08 PM
Last modification on : Friday, July 2, 2021 - 10:20:02 AM
Long-term archiving on: : Monday, March 1, 2021 - 7:43:04 PM

### File

borgis-et-al_HAL.pdf
Files produced by the author(s)

### Citation

Daniel Borgis, Sohvi Luukkonen, Luc Belloni, Guillaume Jeanmairet. Simple Parameter-Free Bridge Functionals for Molecular Density Functional Theory. Application to Hydrophobic Solvation. Journal of Physical Chemistry B, American Chemical Society, 2020, 124, pp.6885-6893. ⟨10.1021/acs.jpcb.0c04496⟩. ⟨cea-02899078⟩

Record views