where N elem is the total number of distinct elements in the system, c i is the molar fraction of each element i, E i is the molar energy of each element i, and ∆E form is the formation energy. We calculated the formation energy for each sample by subtracting the internal energy from the total energy computed with VASP. The histograms of the observed formation energies are shown in Figures and. As calculations are performed for a discrete number of concentrations, for each concentration, the energies of the sampled configurations will be centered around the average formation energy for this concentration. This results in multi-peaked energy histograms in Figures and.