The mystery of abnormally large volume of PbCrO3 with a structurally consistent Hubbard U from first-principles
Institute of Atomic and Molecular Physics, Sichuan
Received in final form: 1 June 2013
Published online: 7 August 2013
PbCrO3 is found experimentally to be a cubic perovskite with an abnormally large lattice constant of about 4.00 Å. To date, no successful first principle calculations have been carried out for cubic PbCrO3 perovskite. Combining the generalized-gradient approximations and a structurally consistent Hubbard U approach, the crystal, electronic and magnetic structures of PbCrO3 are calculated to explore the mystery of abnormally large volume of PbCrO3 in cubic structure. The crystal structure, magnetic order and half-metallic properties of PbCrO3 are determined. For the first time, a structurally consistent Hubbard Ueff of about 8.28 eV for PbCrO3 is calculated based on linear-response approach. With the structurally consistent U obtained by first principles, a cubic structure with a lattice constant of about 3.98 Å for PbCrO3 is obtained successfully. Moreover PbCrO3 is found to be half-metallic ferromagnet with an integral magnet moment of 2.00μB per unit cell. The anomalously large volume of PbCrO3 in cubic structure results from the strongly correlated electron interaction. The results obtained agree well with experimental data.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2013