  First principles calculations were performed to study the ground state
electronic properties of BaFeO3 (BFO) within the density functional theory
(DFT). Adopting generalized gradient approximation (GGA) exchange and
correlation functional and Vosko-Wilk-Nusair correlation energy functional
interpolation, we have systematically conducted the band structure, density of
states and electronic distribution along different crystalline planes.
Calculating results show that band gap in the majority spin band structure and
band gap in the minority spin band structure were found to be 2.7012 eV and
0.6867 eV respectively. Up-spin Fe t2g were fully occupied and down-spin Fe eg
were empty. Moreover, the up-spin Fe eg and down-spin Fe t2g were partially
occupied near the Fermi energy, leading to a finite density of states. The
Fe4+-O-Fe4+ plane superexchange coupling should rearrange the magnetic order to
make the ferromagnetic characteristic being possible, moreover the tetragonal
displacement along the c axis could induce the perovskites materials to acquire
ferroelectric property. These reasons could lead to the fact that the
tetragonal phase BFO could be a potential multiferroics while it was produced
under the very experimental conditions. The charge density along different
crystalline planes were illustrated to show that strong covalent bonding
between O and Fe can be used to investigate the exchange coupling, and this
strong hybridization may further increase the superexchange coupling to enhance
the magnetic ordering.
