Orthorhombic Phase of La_0.5Bi_0.5NiO₃ Studied by First Principles

Abstract

The aim of presented first principles study of La0.5Bi0.5NiO3 is to investigate electronic structure of orthorhombic phase Pbnm. The calculations show that metallicity and magnetism of the system are strongly related with hybridization between Ni 3d and O 2p. To improve the quality of the electronic structure description of the system, especially the treatment of correlation for the Ni 3d, we employ GGA, LDA, and GGA+U , LDA+U . The LSDA results give good agreement with experiment. Thus, the screening effects originating from the hybridized Ni 3d and O 2p electrons are sufficiently strong that they reduce the electronic correlations in the La0.5Bi0.5NiO3, making it a weakly correlated metal.

“Flat/steep band model” for superconductors containing Bi square nets

“…The LSDA + U method [41] was used to treat the strongly correlated 4f and 3d electrons. The values of the parameter U and the exchange integral J for the 4f electrons of the Ce ions are chosen as 8 and 1 eV, while those for the 3d electrons of the Ni ions are chosen as 4 and 1 eV, respectively [42,43]. In this work, the basis sets for Ce, Ni and Bi are 4f 1 5s 2 5p 6 5d 1 6s 2 , 3d 8 4s 2 and 5d 10 6s 2 6p 3 , respectively.…”