Repeats, leading to different computed values, often indicate a lack of convergence of the umbrellas. However, for all simulated systems there is a sufficient overlap between adjacent umbrella histograms (Figures ), which is a key requirement for computing PMFs with WHAM. Additionally, we find that the umbrellas in each repeat are converged in time, as indicated by the convergence of PMF profiles with simulation length (0-2.5, 0-5.0, 0-7.5, 0-10.0 ns for systems 1,2,4,5 and 0-10, 0-20, 0-30, 0-40, 0-50 ns for system 3) (Figures ).