This renewal grant is in support of research in computational statistical mechanics. A variety of projects will be studied which are amenable to solution using advanced computational techniques. Techniques will be developed and refined for the large scale simulation of phase transitions in systems with competing interactions. Dynamical critical phenomena will be studied. Other research topics wil include capillary condensation, high resolution Ising model simulations, finite size effects in the classical Heisenberg model, random systems, magnetic superlattices and surface phase transitions. Various techniques will be used to implement these simulations including Monte Carlo, Monte Carlo renormalization group, molecular dynamics and spin dynamics. Computational simulations of systems composed of many particle represent an alternative to the usual theoretical calculations and experimental investigation. The principal investigator on this grant is an accomplished expert on simulations of physical phenomena. The principal investigator will study a variety of current problems in statistical mechanics which are amenable to solution using computational simulation and will also develop associated algorithms to facilitate these simulations. The research topics are of intrinsic interest in condensed matter physics in addition to having possible application to magnetic materials, surface behavior of materials and algorithm development.