Date of Award

2013

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Chemical and Biomolecular Engineering

First Advisor

Talid Sinno

Second Advisor

Warren D. Seider

Abstract

In this thesis, a coarse-grained lattice Metropolis Monte Carlo (CG-MMC) framework is presented for simulating atomic and molecular fluid systems described by standard molecular force-fields. The CG-MMC technique is demonstrated to be highly thermodynamically consistent with the underlying full resolution problem using a series of detailed comparisons, including vapor-liquid equilibrium phase envelopes and spatial density distributions for the square well, Lennard-Jones argon, and simple point charge (SPC) water models.

The principal computational bottleneck associated with computing a coarse-grained interaction function for evolving particle positions on the discretized domain is addressed by the introduction of new closure approximations. It is shown that the coarse-grained potential can be computed at multiple temperatures and scales using a single set of free energy calculations. Theoretical underpinnings of CG-MMC are further discussed by addressing additional potential sources of error as well as computational advantages.

Two important applications of CG-MMC model are presented. The first application explores the validity of CG-MMC model in non-equilibrium simulations. A variant of the CG-MMC method is developed that enables simulation of coarse-grained non-equilibrium trajectories. It is shown that the resulting NECG-MMC method generates trajectories that are consistent with coarse-grained Langevin dynamics. The second application explores the validity of CG-MMC model in large-scale simulation. Multi-particle move capability is developed and the scaling properties of the CG-MMC approach are studied. A non-equilibrium simulation at large scale is used as a demonstration.

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