Abstract
The electronic structures of the perovskite oxides have been studied in the local-spin density approximation method with the on-site Coulomb interaction parameter U varying from 0.0 to 10.5 eV, and exchange parameter J, from 0.35 to 0.95 eV. It is found that the splitting of the occupiedspin-up bands and the corresponding unoccupied spin-down bands increases almost linearly with the increase of U, while the positions of the completely empty orbitals (both spin-up and -down bands are unoccupied) are not sensitive to the value of U. These features cause the gaps of the compounds to increase first with U, and then they can increase decrease and or even drop to zero The local magnetic moments increase linearly with increasing U. After considering the on-site Coulomb interaction, the binding energies for the perovskites are lowered, and decrease with the increase of U. The exchange parameter J also influences the electronic properties, though not as strongly as that of the U. A group of values of U and J parameters, which can give results closer to that given by experiments, have been found.
- Received 11 May 1999
DOI:https://doi.org/10.1103/PhysRevB.60.15674
©1999 American Physical Society