First principles investigation on the band gap of the ground state of

The band gap of LaCoO3 in ground state is obtained from the generalized gradient approximation (GGA) with on-site Coulomb correction (GGA+U) calculations (U=3.4 eV, J=0.49 eV ), which agrees with the experimental result very well. A series of local spin density approximation (LSDA) with on-site Coulomb corrections (LSDA+U) and GGA+U calculations are performed with various U and J parameters to understand the recently published band gaps of 1.43 eV from LSDA+U (U=8.33 eV ) and 1.0 eV from GGA+U (U=2.7) calculations. The partial density of states (PDOSs) are presented to investigate the origin of the band gap.