The number of atoms per unit cell in FCC structures is ‘4’
Each atom is considered as one sphere.
So the volume of 4 atoms
(4 sphere) = 4 × \(\frac{4}{3}\)πr3 = \(\frac{16}{3}\)πr3
Edge length a = \(2\sqrt2r\)
The volume of the cubic unit cell = a3 = \((2\sqrt2r)^3\)
