Density Functional Theory Study on Spin States of LaCoO3 at Room Temperature

National Natural Science Foundation of China [21033006, 21133004, 21373167]; Ministry of Science and Technology [2010CB732303]The electronic structure of the perovskite LaCoO3 at room temperature structure (293 K) was calculated by using PBE, PBE+U and HSE. Different spin configurations have been considered. Our calculations showed that the choice of the Hubbard U parameter in DFT+U and mixing factor a in HSE significantly influenced the band gap as well as relative energies. For the spin exited states, the optimal value for U and alpha were 3.0 eV and 0.05, respectively. Our calculation also emphasized that when U >= 5.0 eV, PBE+U would lead to unreasonable electronic structure and energy order