A HARTREE-FOCK PERIODIC STUDY OF BULK CERIA

We report an all-electron, non-relativistic computational study of bulk CeO2, performed using the Restricted Hartree-Fock periodic program CRYSTAL. Mechanical, thermodynamic and electronic properties have been analyzed for the ground state of the system. The lattice parameter is found to be 5.385 angstrom, and the bulk modulus 35.7 x 10(11) dyne cm-2 for the lowest energy configuration. The charge transferred from the cation to the anions is calculated as 2.35e per unit cell. We find that the band structure is dominated by metal 5p character in the lower part of the valence band, and by O 2p character in the upper part. Partially covalent bonding is evident between cations, and also between cations and anions. The anion-anion interaction is found to be highly ionic. We discuss the validity of the ionic model for this solid.