In this paper we report an experimental and theoretical study based on a periodic density functional investigation into selected compositions of Pb 1−x Ca x TiO 3 ͑x = 0.0, 0.25, 0.50, and 0.75͒. Based on our findings, we propose that the pseudocubic structure of these perovskites presents a long-range tendency for cubic symmetry, while the short-range displacements bring the solid solution to a tetragonal symmetry. The results are discussed in terms of x-ray diffraction, structural optimized parameters, Raman spectroscopy, band structure, density of states, Mulliken charge, and overlap population.