Electronic structure of cerium hydrides: Augmented-plane-wave linear-combination-of-atomic-orbitals energy bands

Electronic energy bands have been calculated for Ce${\mathrm{H}}_{2}$ and Ce${\mathrm{H}}_{3}$ using the augmented-plane-wave method and have been fitted by the linear-combination-of-atomic-orbitals interpolation scheme. The partial densities of states and the numbers of electrons on atomic orbitals indicate that hydrogen in Ce${\mathrm{H}}_{2}$ is almost anionlike. When going from Ce${\mathrm{H}}_{2}$ to Ce${\mathrm{H}}_{3}$, shallow bonding levels are found to form between the third hydrogen state and conduction electrons of Ce${\mathrm{H}}_{2}$, other features of Ce${\mathrm{H}}_{2}$ being little affected by it. Thus the rare-earth dihydrides are regarded as ionic compounds similar to the saline-element dihydrides except for the presence of $d$-like conduction electrons.