The main distinction between the methodology in this study and in Ref. 46 is the ability to add external potential to orbitals with different m l . For example, the method here allows us to apply some amount of energy to one or two of the p-orbitals instead of to all three uniformly. In doing so, we are able to raise the energies of the Γ - 4 and Γ - 5 ⊕ Γ - 6 bands in rock-salt SnSe as opposed to raising the energies of all three conduction bands (Figure ).