(30a) Molecular Simulation of Phase Equilibria and Self-Assembly: Progress and Challenges

This lecture provides a review of molecular simulation methods for modeling phase equilibria and self-assembly, topics greatly influenced by Prof. Keith Gubbins. The Gibbs ensemble is a direct approach proposed over twenty years ago that is suitable for calculations of moderate accuracy. Combined with Kofke’s Gibbs-Duhem integration, it allows the relatively routine calculation of phase diagrams for given intermolecular potentials. Alternatively, histogram reweighting Monte Carlo methods provide good accuracy near critical points and provide paths for overcoming hysteresis and long time scales inherent in self-assembly of surfactants and polymers. In recent years, with the advent of fast, scalable, open-source packages for molecular dynamics calculations the time scales over which self-assembly and microphase separation can be studied have been extended to μs, even for realistic potential models with explicit solvent. However, there is still a significant need for development of coarse-grained models that correctly capture structure and thermodynamics in order to extend the time and length scales of systems that can be modeled.