Relativistic Energy Band Structure and Properties ofγ-Uranium

The electronic band structure of the high-temperature phase of uranium has been determined by means of the symmetized relativistic augmented-plane-wave method. Six different crystal potentials (three atomic starting configurations, $5f^{4}7s^2$, $5f^{3}6d^{1}7s^2$, and $5f^{2}6d^{2}7s^2$, each taken together with $\alpha =\frac{2}{3}$ and $\alpha =1\mathrm{}$ approximations for exchange) were employed in the warped-muffin-tin approximation. The relativistic effects are found to be very important and result in $5f$ bands which overlap and hybridize strongly with the very broad "$7s-p$" and broad $6d$ bands (which in the absence of the $5f$ states are found to be those typical of a high-atomic-number transition metal). The nonrelativistic energy bands are found to be incorrect in many ways. A calculated density of states shows considerable structure reflecting the $s-d-f$ hybridization and a relatively high density of states (1.45 states per atom eV) at the Fermi energy. The Fermi surface is found to be complicated and to consist of two hole and one electron surfaces.