Using the input data for each of the datasets, global correlation lengths were obtained via the semivariogram method described in Section 2.3 with a bin width of 1 d • Ω . Figure shows the empirical semivariograms together with the analytical fits used to obtain the values of the respective correlation lengths. The change in concavity suggests that GBE correlations for Ni and Fe are Gaussian in nature (Section S2.2).