  First principle calculations were performed to study the ground state
electronic properties of Barium titanate within the density functional theory
(DFT). In our DFT computations, we used Vosko-Wilk-Nusair correlation energy
functional and generalized gradient approximation (GGA) exchange and
correlation energy functional as suggested by Perdew and Wang (PWGGA). The band
structure, total density of states (DOS) and partial DOS have been
systematically conducted to investigate the electronic configuration of this
prototype ferroelectric perovskits compound. The band gap was 1.92 eV within
our approach, and the quasi-flat band at -17 eV and -10 eV were attributed to
the O 2s and Ba 5p states respectively, which was in good agreement with the
corresponding total DOS and partial DOS. From the DOS investigation, it can be
seen that the Ti eg state intended to interact with the oxygen octahedral
orbitals to form the p-d hybridization. Moreover the strong p-d overlap and
bonding can be observed in the electronic density redistribution along the
different crystalline planes with respect to the corresponding space group, and
the electronic isodense have been shown along the (001), (100), (110) and (111)
crystal planes. From these electronic density maps, the strong bonding between
Ti and O atoms can even be observed in the (111) crystalline plane.
