The compound BaTiO₃ has a perovskite structure. Considering the following ratio of radii: (R (O^2-) = 0.146nm, R (Ti⁴⁺ ) = 0.071nm, R (Ba²⁺) = 0.113nm, Na = 6.023x10²³ mol-1, Patm (Ba) = 137.33 g / mol ; Patm (Ti) = 47.88 g / mol; Patm (O) = 15.99 g / mol;

b) Determine the lattice parameters of the unit cell

c) Determine the planar density in the (101) plane (in ions / nm²)

d) Determine the volumetric density (in g / cm³)

Ti Ba (101) d = 2a