Monte Carlo methods for the study of cation ordering in minerals

This paper reviews recent applications of Monte Carlo methods for the study of cation ordering in minerals. We describe the program Ossia99, designed for the simulation of complex ordering processes and for use on parallel co mputers. A number of applications for the study of long-range and short-ran ge order are described, including the use of the Monte Carlo methods to com pute quantities measured in an NMR experiment. The method of thermodynamic integration for the determination of the free energy is described in some d etail, and several applications of the method to determine the thermodynami cs of disordered systems are outlined.