Cubic Crystal System

(1) Simple cubic unit cell: Lattice points (atoms) are located only at corners of the cube.

(2) Body centered unit cell: Lattice points are located at corners as well as body centre of the cube.

(3) Face centered unit cell: Lattice points are located at corners and centre of faces of the cube.
 

Unit cell	Number of Atoms			Total number of atoms per unit cell	Space Lattice
	At corners	At body center	On faces
Primitive		Zero	Zero	One
FCC		Zero		Four
BCC		1	Zero	Two

Contribution by an atom in a cubic unit cell.
 

Address of an atom    (Lattice Point)	Corner of Cube	Edge of Cube	Face of Cube	Body centre
Contribution				One per unit Cell