Noble gases
All noble gases crystallize in ccp structure except helium which has hcp structure.
Metals
Be, Cd, Co, Mg and Zn - have hcp structure.
Al, Ag, Au, Cu, Ni and Pt - have ccp structure.Molecular substances
Molecular substance having nearly spherical molecules have closed packed arrangements.
Examples: Solid H2 has hcp structure, while solid CH4, HCl, H2S have ccp structure.Ionic substances
In ionic substances the larger ions form the close packed arrangement and smaller ions occupy the voids.
Example:
