Electronic structure of hydrogen and oxygen chemisorbed on plutonium: Theoretical studies

The film linearized-muffin-tin-orbital method has been used to calculate the electronic structure of hydrogen and oxygen chemisorbed on plutonium. The calculated work functions are larger than that obtained for a clean Pu surface. This suggests that a change in the surface dipole moment is induced by the chemisorbed H and O atoms. For the H chemisorbed state it is found that the fourfold-bridging position is stable with regard to motion out of or into the plutonium surface plane---with only a small relaxation effect, and that the energy gained when the H atoms chemisorb on the Pu surface is 4.0 eV per atom. The localized, spin-polarized 5f electrons in PuH2 are found to induce a substantial conduction-band moment. The calculations suggest that the electronic structure of the oxygen chemisorbed state is more covalent than the hydrogen chemisorbed state