Molecular Simulation of Phase Equilibria : Progress and Challenges

A major topic in chemical engineering thermodynamics is the calculation of the phase behavior of pure components and mixtures from molecular-based information. The Gibbs ensemble and grand canonical Monte Carlo methods enable the calculation of phase diagrams for fluids composed of complex, realistic potentials. For solid phases and for determination of activity coefficients and solubilities in electrolyte solutions, thermodynamic integration methods provide a direct path to the phase behavior and thermodynamic properties. Alternatively, open-source fast and scalable molecular dynamics codes have been developed that can be used in two-phase simulations of phase equilibria. The main remaining challenges in this area are related to the inadequacies of the current generation of force fields, which lack important physical features such as polarizability. Work in this area has been deeply influenced by the seminal contributions of Prof. Gubbins over the past several decades.