Question

In a cubic unit cell, what is the contribution to the unit cell of the particle present at the corner?

Answer 1

In a cubic unit cell, each corner particle is shared by 8 adjacent unit cells, meaning only 1/8th of each corner particle belongs to a single unit cell. Since a cubic unit cell has 8 corners, the total contribution of corner particles to one unit cell is `8 xx 1/8 = 1` particle.