The mineral perovskite has a structure that is the prototype of many $\mathrm{A}\mathrm{B}{\mathrm{X}}_3$ solids particularly oxides. The perovskite structure is cubic with A atoms surrounded by 12 X atoms and the B atoms surrounded by 6 X atoms. The sum of charges on the cations A and B must be $+6$; it can be achieved in several ways $({\mathrm{A}}^{2+}{\mathrm{B}}^{4+}$ and ${\mathrm{A}}^{3+}{\mathrm{B}}^{3+}$ among them). Oxidation state of titanium in $\mathrm{C}\mathrm{a}\mathrm{T}\mathrm{i}{\mathrm{O}}_3$ (Perovskite) is :