A Full-Potential-Linearized-Augmented-Plane-Wave Electronic Structure Study of delta-Plutonium and the (001) Surface

Abstract

The electronic and geometric properties of bulk fcc delta-plutonium and the quantum size effects in the surface energies and the work functions of the (001) ultra thin films (UTF) up to 7 layers have been investigated with periodic density functional theory calculations within the full-potential linearized augmented-plane wave (FP-LAPW) approach as implemented in the WIEN2k package. Our calculated equilibrium atomic volume of 178.3 a.u.^3 and bulk modulus of 24.9 GPa at the fully relativistic level of theory, i.e. spin-polarization and spin-orbit coupling included, are in good agreement with the experimental values of 168.2 a.u.^3 and 25 GPa (593 K), respectively. The calculated equilibrium lattice constants at different levels of approximation are used in the surface properties calculations for the thin films. The surface energy is found to be rapidly converged with the semi-infinite surface energy predicted to be 0.692eV at the fully-relativistic level.