(220i) A Graph-Based Approach for Systematic Molecular Coarse-Graining

An overarching aspiration in soft-materials research is the theory-based design of systems with desired functional properties. Some examples include identifying polymer chemistries and architectures that facilitate fast ion conduction for use in batteries or synthesizing polymers with requisite solubility and interactions that enable supra-molecular assembly for application as biomaterials. While computational statistical mechanics provides a framework to establish structure-property relationships that facilitate design, many important phenomena require descriptions over a broad range time and length scales that extend beyond the capabilities of atomistic molecular dynamics and require alternative simulation strategies. At the same time, these alternative simulation strategies should be generalizable and automatable for purposes of design or materials characterization.

In this talk, I will discuss a novel coarse-graining approach that enables efficient simulation of molecular systems at a targeted resolution. A central feature of this coarse-graining approach is a systematic, graph-theoretic coarse-graining scheme, which provides an unambiguous and automated way to generate coarse-grained representations that preserve chemical topology and reflect chemical functionalization. I first illustrate the approach using a series of simple systems before application to a series of high-molecular weight polysaccharides, for which atomistic simulations are infeasible. Using a series of models with increasing levels of “coarseness,” I characterize relevant structural and dynamic properties and assess how the choice of coarse-grained representation affects such predictions at different time and length scales. Overall, these studies provide valuable mechanistic insight, and the described methodology provides a framework with significant utility for the coarse-grained study of various molecular systems.