No. of lattice points = No. of octahedral voids =21​× No. of tetrahedral voids in ccp structure ∴ No. of atoms of B = 4 No. of atoms of A=21​× No. of octahedral voids =21​×4=2 No. of atoms of O= All tetrahedral voids =2× No. of lattice points =2×4=8 Hence, A:B:O=1:2:4 Therefore, the formula of the compound is AB2​O4​