First-principles calculations based on the projector augmented-wave (PAW) technique have been applied to the prediction of materials properties of $\alpha$-uranium and its (001) surface. The results of the PAW calculations are shown to be comparable in accuracy to the full-potential calculations reported elsewhere. In addition to calculating lattice constants and elastic moduli, the vacancy formation energy $\left(1.95\mathrm{eV}\right)$, (001) surface relaxation ($-3.5\%$ for ${\delta }_{12}$ and $+1.2\%$ for ${\delta }_{23}$), (001) surface energy $(1.4\mathrm{J}∕{\mathrm{m}}^2)$, and (001) work function $\left(3.6\mathrm{eV}\right)$ were also obtained. The overall agreement with experiment is satisfactory. Using an elastic model for brittle-crack failure, a yield stress of $430\mathrm{MPa}$ was estimated. Further exploration of materials failure modes (such as plastic deformation) awaits a larger-scale atomistic treatment. Full spin-orbit and scalar relativistic calculations were shown to give results with similar levels of accuracy compared to experiment.

• Received 2 November 2007

DOI:https://doi.org/10.1103/PhysRevB.77.094119