The $E(k)$ values were computed for the equivalent of 2048 points in the Brillouin zone and for energies ranging from the bottom of the $4s$-band to approximately 2 Ry above the Fermi energy. From these calculations the Fermi energy, Fermi surface, and density of states were determined. Comparison of results with experiment shows not only qualitative but in most cases quantitative agreement. Agreement with recent independent theoretical work by Segall suggests an accurate solution of Schr\"odinger's equation for the potential used has been obtained.