A new charge model, called Charge Model 4 (CM4), and a new continuum solvent model, called Solvation Model 6 (SM6), are presented. Using a database of aqueous solvation free energies for 273 neutrals, 112 ions, and 31 ion-water clusters, parameter sets for the mPW0 hybrid density functional of Adamo and Barone (Adamo, C.; Barone, V. J. Chem. Phys. 1998, 108, 664-675) were optimized for use with...

Published solubility data for 4,5-dihydroxyanthraquinone-2-carboxylic acid dissolved in several organic solvents of varying polarity and hydrogen-bonding character are used to calculate the Abraham model solute descriptors. Calculated descriptor values suggest that engages intramolecular hydrogen formation between two phenolic hydrogens proton acceptor sites (the lone electron pairs) on neighbo...

Implicit solvation is a mean force approach to model solvent forces acting on a solute molecule. It is frequently used in molecular simulations to reduce the computational cost of solvent treatment. In the first instance, the free energy of solvation and the associated solvent-solute forces can be approximated by a function of the solvent-accessible surface area (SASA) of the solute and differe...

A novel method for fast and accurate evaluation of the generalized Born radii in macromolecular solvation electrostatics calculations is proposed, based on the solvent accessibility of the first two solvation layers around an atom. The reverse generalized Born radii calculated by the method have correlation coefficient of 98.7% and RMSD of 0.031 A(-1) with the values obtained using a precise bu...

Recent calorimetric measurements of the solvation enthalpies of some dipeptide analogs confirm our earlier prediction that the principle of group additivity is not valid for the interaction of the peptide group with water. We examine the consequences for understanding the properties of peptide solvation. A major consequence is that the current value of the peptide-solvation enthalpy, which is a...

Changes in the (31)P NMR chemical shift of tri-n-butylphosphine oxide have been measured as function of solvent composition in a number of binary solvent mixtures. The data were analysed using a model that separates the contributions of specific H-bond interactions with the first solvation shell and the non-specific effects of the bulk solvent on the chemical shift. This allowed measurement of ...

We present molecular dynamics simulations of a simple dimer immersed in a Lennard-Jones LJ fluid to test the validity of the solvation pressure model in a system where we attempt to isolate the general and ubiquitous solvation pressure. The solvated dimer acts as a simple pressure gauge in a system where the cohesive energy density CED of the solvent is fixed. We study the dimer bond length as ...

The effect of SDS (0.03-0.07 M) and Brij-35(0-0.003 M) concentrations and temperature on retention parameters of 30 solutes in micellar reversed- phase liquid chromatography systems were studied using solvation parameter model. The system constants were determined by multiple linear regression analysis from experimental values of the retention factors with known descriptors by computer usin...