Which of the following statements correctly describe the ideal Antifluorite () crystal structure? — Solid State Chemistry Question

💡 Solution & Explanation

In the antifluorite structure, the positions of cations and anions are reversed compared to fluorite. The larger $O^{2-}$ anions form the ccp (fcc) lattice, while the smaller $Na^+$ cations occupy all $8$ tetrahedral voids. Consequently, each $Na^+$ is surrounded by $4$ $O^{2-}$ (C.N. 4), and each $O^{2-}$ is surrounded by $8$ $Na^+$ (C.N. 8).