Electronic structures of quasi-one-dimensional ferrimagnetic insulator Ca3Co2O6
The electronic structures of quasi-one-dimensional ferrimagnetic Ca3Co2O6 are investigated using the generalized gradient approximation (GGA) as well as the GGA plus on-site Coulomb interaction (GGA+U GGA + U ) scheme. GGA+U GGA + U calculations reveal that the interchain ferrimagnetic Ca3Co2O6 is a MottHubbard insulator rather than a metal given from GGA. In addition, we found an on-site U  induced 3z2?r2 3 z 2 ? r 2 orbital ordering on Copri sublattice which drives the intrachain ferromagnetic coupling along c-axis. Our findings suggest that strong electron-electron correlation plays an important role in Ca3Co2O6.
orbital ordering first-principles calculations strong correlation