Accurate modeling of distance-dependent charge transfer and polarization in chemical potential equalization methods

PHYS 306

G. Lee Warren, and Sandeep Patel, Chemistry and Biochemistry, University of Delaware, Newark, DE 19716
Polarizable force fields present an advantage over traditional fixed-charge models in that they explicitly account for variations in the local electrostatic environment occurring at phase boundaries and at the surface and interior of proteins. Polarizable models are also essential for the qualitative prediction of effects such as the surface enrichment of anions at the vapor interface of aqueous salt solutions. However, such models often neglect charge transfer effects and the environmental dependence of the molecular polarizability which play an important role in water mediated interactions of charged species. Chemical potential equalization methods which model polarization effects via charge redistribution are uniquely suited to modeling these effects. We present various approaches to constructing and parameterizing such force fields and address certain model instabilities associated with monomer dissociation. We apply our results to the development of solvated ion models suitable for modeling charge transfer effects at the solution-vapor interface of aqueous salt solutions.

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