Close packed Structure

Co-ordination number: - The total number of atom which is directly attached with one atom that is called co-ordination number.

	Co-ordination number
1-Dimention	2
2-Dimention	AAA –type 4, ABAB-type 6
S.C.C.	6
B.C.C.	12
F.C.C.	8

Close packed Structure 

The term "closest packed structures" refers to the most tightly packed or space-efficient composition of crystal structures (lattices). Imagine an atom in a crystal lattice as a sphere. ... These arrangements are called closest packed structures. The packing of spheres can describe the solid structures of crystals.