Hi Kicaj, Just, to follow up on Bruce's comment: A single cluster with 1 Al absorber and no Al scatterers does not really describe "1%" or even "0.5%" doping. It is "0%" doping. By "1% Al doping", you (probably) really mean that each Zn site has a 1% chance of being occupied by Al. I think that's what you have to simulate. That means generated many (several hundred I would expect) clusters with each Zn site having 1% Al occupancy, and summing the results of those calculations. I don't think the mean free path or size of the subcluster for the full multiple scattering matter here, except as it guides how large a cluster you need to consider. The size of the cluster needed for convergence is important, but does not really dictate an occupancy. What you want it a set of clusters that does simulate the proper doping level. --Matt