The downfolded NMTO band structures were then compared with the bands computed employing the full NMTO basis set. The band structure computed by only placing an s-orbital on every empty sphere (ISQ) and choosing an energy mesh that spanned the valence band was able to describe the valence band well, except at the R-point where this band is triply degenerate. In this calculation, all of the partial waves on the Ca atoms were downfolded and the s-like partial waves on the empty spheres were used in the basis. The resulting WF is plotted in the manuscript, and it could be described as forming from a constructive overlap of spd-hybrid orbitals of the 8 Ca atoms that surround the empty sphere. This Wannier-function differs from the one calculated by as it spans only one band, whereas previously a basis that also included the 5d orbitals on the Ca atoms was constructed.