Critical tests of perturbative and linear response theories for the hydration of polar and nonpolar solutes

PHYS 312

Jill Tomlinson-Phillips,, Robin C. Underwood,, and Dor Ben-Amotz, Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907
Theoretical, computational, and experimental results are combined to investigate hydrophobic hydration on both small and large length scales. The results are used to critically test perturbative and linear response theories. Molecular dynamics and coupling parameter integration simulations are used to probe the interaction energy between water and solutes of various sizes and polarities. The total interaction energy is separated into (WCA) repulsive and attractive (Lennard-Jones and coulombic) components to independently determine energetic and entropic contributions to the associated free energy. Comparisons of exact (simulation and/or experimental) results with 1st order perturbation and linear response predictions are used to critically test various analytical approximation strategies for describing a given hydration process, including recently derived coupling parameter expressions for the sum of all higher order contributions, beyond the first or second term in the associated perturbative series.

PHYS Poster Session - Water Mediated Interactions
7:30 PM-10:00 PM, Wednesday, August 20, 2008 Pennsylvania Convention Center -- Hall C, Poster

Division of Physical Chemistry

The 236th ACS National Meeting, Philadelphia, PA, August 17-21, 2008