(663i) On the Development of Intermolecular Potentials for Coarse-Grained Models

Recently, coarse-grained (CG) modeling and simulation have attracted tremendous attention in modeling a variety of problems in chemical engineering. However, there is a lack of theoretical foundations and systematic procedures in constructing the intermolecular potential of a CG model. In this work, the development of intermolecular potentials for coarse-grained models is formulated based on statistical mechanics. The connection between a user defined CG model and the underlying atomistic representation is thus established analytically. Two numerical methodologies, force-matching and fluctuation-matching that are resulted from our statistical mechanical formulation will then be presented. By applying the force-matching or the fluctuation-matching method, the CG intermolecular potential can be developed directly from atomistic simulations. The results of applying these two methods to develop the CG models of liquid water, protein actin monomer, and the actin filament will be presented. The resulting structural (pair-correlation functions) and mechanical properties (persistence length) of these CG models reproduce the results of atomistic simulations, indicating the capability of our multi-scale CG methods in extracting useful information from the underlying fine-grained simulations.