Question

Explain how much portion of an atom located at

(i) corner and

(ii) body-centre of a cubic unit cell is part of its neighbouring unit cell.

Answer 1

i. An atom located at corner of a cubic unit cell is shared by eight neighbouring unit cells. Hence 1/8^th of an atom located at corner of a cubic unit cell is part of its neighbouring unit cell.

ii. An atom located at body-centre of a cubic unit cell is not shared by any other unit cell. Hence, it is not a part of the neighbouring unit cell.