Structural properties of PbTiO₃ and PbZr_xTi_1-xO₃: A quantum-chemical study

We investigate the structural and electronic properties of pure and Zr-doped PbTiO₃ crystals. The nature of atomic relaxation around the Zr impurity is studied through quantum-chemical simulations based on the Hartree-Fock theory and a periodic large unit cell model adopted within the so-called intermediate neglect of differential overlap approximation. The most stable defect configurations are predicted for different impurity concentrations. The results obtained are compared with those from other theoretical studies and a number of experimental measurements carried out on this technologically important perovskite-type crystal.