MULTIPHASE EQUILIBRIA USING THE GIBBS ENSEMBLE MONTE-CARLO METHOD

The Gibbs ensemble simulation method is extended to multiphase equilib ria by increasing the number of boxes that can be used concurrently in the simulation. Atoms are moved within each box and pairs of boxes ar e selected at random for the volume and particle exchange moves. The e quivalence between the Gibbs ensemble with an arbitrary number of boxe s and the corresponding canonical ensemble is established. Simulations of two-component, three-phase equilibria and three-component, four-ph ase and three-phase equilibria are demonstrated for simple model syste ms, and the model phase diagrams are determined.