+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Modeling molecular and ionic absolute solvation free energies with quasichemical theory bounds



Modeling molecular and ionic absolute solvation free energies with quasichemical theory bounds



Journal of Chemical Physics 129(13): 134505



A recently developed statistical mechanical quasichemical theory (QCT) has led to significant insights into solvation phenomena for both hydrophilic and hydrophobic solutes. The QCT exactly partitions solvation free energies into three components: (1) Inner-shell chemical, (2) outer-shell packing, and (3) outer-shell long-ranged contributions. In this paper, we discuss efficient methods for computing each of the three parts of the free energy. A Bayesian estimation approach is developed to compute the inner-shell chemical and outer-shell packing contributions. We derive upper and lower bounds on the outer-shell long-ranged portion of the free energy by expressing this component in two equivalent ways. Local, high-energy contacts between the solute and solvent are eliminated by spatial conditioning in this free energy piece, leading to near-Gaussian distributions of solute-solvent interaction energies. Thus, the average of the two mean-field bounds yields an accurate and efficient free energy estimate. Aqueous solvation free energy results are presented for several solutes, including methane, perfluoromethane, water, and sodium and chloride ions. The results demonstrate the accuracy and efficiency of the methods. The approach should prove useful in computing solvation free energies in inhomogeneous, restricted environments.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 054413857

Download citation: RISBibTeXText

PMID: 19045103

DOI: 10.1063/1.2985613


Related references

Cluster-continuum quasichemical theory calculation of the lithium ion solvation in water, acetonitrile and dimethyl sulfoxide: an absolute single-ion solvation free energy scale. Physical Chemistry Chemical Physics 17(40): 26745-26755, 2015

Prediction of Absolute Solvation Free Energies using Molecular Dynamics Free Energy Perturbation and the OPLS Force Field. Journal of Chemical Theory and Computation 6(5): 1509-1519, 2010

Computation of methodology-independent ionic solvation free energies from molecular simulations. II. The hydration free energy of the sodium cation. Journal of Chemical Physics 124(22): 224501, 2006

Computation of methodology-independent ionic solvation free energies from molecular simulations. I. The electrostatic potential in molecular liquids. Journal of Chemical Physics 124(12): 124106, 2006

1-Octanol/Water Partition Coefficients of n-Alkanes from Molecular Simulations of Absolute Solvation Free Energies. Journal of Chemical Theory and Computation 5(9): 2436-2446, 2009

An SCF Solvation Model for the Hydrophobic Effect and Absolute Free Energies of Aqueous Solvation. Science 256(5054): 213-217, 1992

Aqueous solvation free energies of ions and ion-water clusters based on an accurate value for the absolute aqueous solvation free energy of the proton. Journal of Physical Chemistry. B 110(32): 16066-16081, 2006

Electrostatic solvation free energies of charged hard spheres using molecular dynamics with density functional theory interactions. Journal of Chemical Physics 147(16): 161716, 2017

SM6:  A Density Functional Theory Continuum Solvation Model for Calculating Aqueous Solvation Free Energies of Neutrals, Ions, and Solute-Water Clusters. Journal of Chemical Theory and Computation 1(6): 1133-1152, 2005

Fast Computation of Solvation Free Energies with Molecular Density Functional Theory: Thermodynamic-Ensemble Partial Molar Volume Corrections. Journal of Physical Chemistry Letters 5(11): 1935-1942, 2014

Equivalence of M- and P-Summation in Calculations of Ionic Solvation Free Energies. Journal of Physical Chemistry. a 121(7): 1525-1530, 2017

Improving the Prediction of Absolute Solvation Free Energies Using the Next Generation OPLS Force Field. Journal of Chemical Theory and Computation 8(8): 2553-2558, 2012

Modeling free energies of solvation in olive oil. Molecular Pharmaceutics 5(6): 1064-1079, 2009

Modeling Free Energies of Solvation in Olive Oil. Molecular Pharmaceutics 5(6): 1064-1079, 2008

Computations of Absolute Solvation Free Energies of Small Molecules Using Explicit and Implicit Solvent Model. Journal of Chemical Theory and Computation 5(4): 919-930, 2009