IMF2017

Optimization of BaTiO₃ crystal unit cell was realized with WC and VdW-DF-C09 exchange-correlation functional under different hydrostatic pressure from -100 to 100 GPa. Thus, changes in the crystal lattice parameters and volume are presented and discussed, as well as changes in the different Ba-O and Ti-O bond lengths. While the self-consistent calculations (scf) were realized using HSE functional in order to obtain electronic band structure, density of state (DOS) and optical properties. Löwdin charge analysis, related to charge transfer of Ba, Ti, and O, shows the nature of the atomic bonds as function of the hydrostatic stress, including the contribution of empty orbits 6p, 5d and 4f from Ba atoms, 3d and 4f from Ti atoms and 3d and 4f from O atoms. Finally, the dielectric function imaginary part spectra, from 0 to 15 eV, are presented and discussed.