What is the size of the largest atom that could be fit into octahedral holes of the lattice without — Solid State Chemistry Question

💡 Solution & Explanation

In FCC, 4 * r_Cu = a * sqrt(2) => r_Cu = a * sqrt(2) / 4. Given a = 0.5 / sqrt(2) nm => r_Cu = (0.5/sqrt(2)) * sqrt(2) / 4 = 0.125 nm. The radius of the largest atom that fits in an octahedral void is r_oct = 0.414 * r_Cu = 0.414 * 0.125 = 0.05175 nm \u2248 0.052 nm.