A solvation-free-energy functional: A reference-modified density functional formulation

Abstract

The three-dimensional reference interaction site model (3D-RISM) theory, which is one of the most applicable integral equation theories for molecular liquids, overestimates the absolute values of solvation-free-energy (SFE) for large solute molecules in water. To improve the free-energy density functional for the SFE of solute molecules, we propose a reference-modified density functional theory (RMDFT) that is a general theoretical approach to construct the free-energy density functional systematically. In the RMDFT formulation, hard-sphere (HS) fluids are introduced as the reference system instead of an ideal polyatomic molecular gas, which has been regarded as the appropriate reference system of the interaction-site-model density functional theory for polyatomic molecular fluids. We show that using RMDFT with a reference HS system can significantly improve the absolute values of the SFE for a set of neutral amino acid side-chain analogues as well as for 504 small organic molecules.

DOI: 10.1002/jcc.23942

Cite this paper

@article{Sumi2015ASF, title={A solvation-free-energy functional: A reference-modified density functional formulation}, author={Tomonari Sumi and Ayori Mitsutake and Yutaka Maruyama}, journal={Journal of computational chemistry}, year={2015}, volume={36 18}, pages={1359-69} }