A coarse-grained Monte Carlo method designed for the simulation of vacancy-mediated diffusion phenomena was presented. A coarse-grained master equation was derived from the atomic scale master equation using an assumption of local equilibrium within each coarse-grained cell. Atomic kinetic Monte Carlo simulations were used to perform both the thermodynamic and the kinetic parameterization of the coarse-grained simulations. Quantitative reproduction of flux couplings was achieved in the coarse-grained simulation. The ability of the method to simulate kinetics controlled by diffusion such as a precipitate dissolution and the decay of sinusoidal modulations of the concentration field was illustrated for body-centered-cubic model alloys with a clustering tendency. It was shown in the case of a model of the Fe-Cu alloy previously developed that the use of this method could reduce the computational cost of a kinetic simulation by several orders of magnitude.

Coarse-Grained Kinetic Monte Carlo Simulation of Diffusion in Alloys. T.Garnier, M.Nastar: Physical Review B, 2013, 88[13], 134207