We also calculated band structures with the pslibrary and Pseudo-Dojo pseudopotentials, using the SeeK-path conventions. We used the "normal" level cutoffs recommended by Pseudo-Dojo. The two pseudopotential sets gave nearly identical band structures. Additionally, we calculated dielectric functions with a uniform k-point grid. Convergence tests were performed to ensure enough points were used, and in each case, >8×10 4 /n (n =number of atoms in the cell) k-points were used. The dielectric function was used to calculate the optical extinction coefficient, k, which is directly proportional to the absorption coefficient, α.