Solvation free energy calculations using continuum dielectric model for the solvent and gradient-corrected density functional theory for the solute

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp951780e· OSTI ID:199374

Tawa, G J; Martin, R L; Pratt, L R; Russo, T V ^[1]

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1. Los Alamos National Lab., NM (United States)

Electrostatic solvation free energies are calculated using a self consistent reaction field (SCRF) procedure that combines a continuum dielectric model of the solvent with both Hartree-Fock (HF) and density functional theory (DFT) for the solute. Several molecules are studied in aqueous solution. They comprise three groups: nonpolar neutral, polar neutral, and ionic. The calculated values of {Delta}G{sup e1} are sensitive to the atomic radii used to define the solute molecular surface, particularly to the value of the hydrogen radius. However, the values of {Delta}G{sup e1} exhibit reasonable correlation with experiment when a previously determined, physically motivated set of atomic radii were used to define the van der Waals surface of the solute. The standard deviation between theory and experiment is 2.51 kcal/mol for HF and 2.21 kcal/mol for DFT for the 14 molecules examined. The errors with HF or DFT are similar. The relative difference between the calculated values of {Delta}G{sup e1} and experiment is largest for nonpolar neutral molecules, intermediate for polar neutral molecules, and smallest for ions. This is consistent with the expected relative importance of nonelectrostatic contributions to the free energy that are omitted in the model. 92 refs., 4 figs., 6 tabs.

• OSTI ID: 199374
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 5 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
99 GENERAL AND MISCELLANEOUS
ACETAMIDE
ACETONITRILE
AMINES
ATOMIC RADII
BENZENE
CALCULATION METHODS
ETHYLENE
EXPERIMENTAL DATA
FREE ENERGY
HARTREE-FOCK METHOD
MATHEMATICAL MODELS
METHANE
METHANOL
MOLECULES
SOLUTES
SOLVATION
SOLVENTS
THEORETICAL DATA