MST continuum study of the hydration free energies of monovalent ionic species.

TitleMST continuum study of the hydration free energies of monovalent ionic species.
Publication TypeJournal Article
Year of Publication2005
AuthorsCurutchet, Carles, Bidon-Chanal Axel, Soteras Ignaci, Orozco Modesto, and F Luque Javier
JournalJ Phys Chem B
Date Published2005 Mar 3
KeywordsCarboxylic Acids, Chemical, Chemistry, Entropy, Hydrogen-Ion Concentration, Ions, Models, Monte Carlo Method, Niacin, Physical, Solvents, Statistical, Theoretical, Thermodynamics, Water

In this study, we revisit the protocol previously proposed within the framework of the Miertus-Scrocco-Tomasi (MST) continuum model to define the cavity between the solute and solvent for predicting hydration free energies of univalent ions. The protocol relies on the use of a reduced cavity (around 10-15% smaller than the cavity used for neutral compounds) around the atom(s) bearing the formal charge. The suitability of this approach is examined here for a series of 47 univalent ions for which accurate experimental hydration free energies are available. Attention is also paid to the effect of the charge renormalization protocol used to correct uncertainties arising from the electron density located outside the solute cavity. The method presented here provides, with a minimum number of fitted parameters, reasonable estimates within the experimental error of the hydration free energy of ions (average relative error of 4.7%) and is able to reproduce solvation in water of both small and large ions.