Calculate the number of particles (atoms) per unit cell in a FCC crystal lattice.

Explanation

Step-1: Number of corners = 8
Step-2: The contribution of corner =`1/8`
Step-3: Number of faces = 6
Step-4: Contribution at the face =`1/2`
Step-5: Number of particle in FCC
`8" corners "xx 1/8 `size of atom per corner = `8 xx 1/8 = 1`
6 `faces xx 1/2` size of atom per face = `6 xx 1/2 = 3` atoms
No. of particles in the unit cell of FCC = `(8 xx 1/8)+(6 xx 1/2) = 1+3 = 4` atoms.