In this simulation, we assume that two grain boundaries with different diffusivities are randomly distributed in a 3D Voronoi grain boundary network. The tool calculates the effective diffusivity across the system.
The simulation time with the default parameter values is approximately 2 minutes. This can be reduced by decreasing the value of "Number of samples" parameter at the cost of reduced accuracy. For number of samples = 1000, the error is around 5%.