H The mineral perovskite is composed of calcium, oxygen, and titanium; its uses as a material span energy production, environmental containment, and communications. Pictured below is the cubic perovskite unit cell. Cations occupy the corners and body center of the unit cel while anions occupy the face-centered positions. Determine the formula unit for perovskite. Solution There are 8 corners and 1 body center. 8 corners are shared by 8 different atoms. Hence for one unit cell, the contribution of one atom is 1/8. Hence, The total number of Calcium cations (corners) = 8 (1/8) = 1 The total number Titanium atoms (body center) = 1 The anions occupy Face centers (6 faces), hence the total number of anions = 6 * (1/2) = 3 ions Hence, the formula is CaTiO 3 . .

1. H The mineral perovskite is composed of calcium, oxygen, and titanium; its uses as a material
span energy production, environmental containment, and communications. Pictured below is the
cubic perovskite unit cell. Cations occupy the corners and body center of the unit cel while
anions occupy the face-centered positions. Determine the formula unit for perovskite.
Solution
There are 8 corners and 1 body center. 8 corners are shared by 8 different atoms. Hence for one
unit cell, the contribution of one atom is 1/8.
Hence, The total number of Calcium cations (corners) = 8 (1/8) = 1
The total number Titanium atoms (body center) = 1
The anions occupy Face centers (6 faces), hence the total number of anions = 6 * (1/2) = 3 ions
Hence, the formula is CaTiO 3 .