Polytypism
Solids crystallized in more than one phases, each having different crystal symmetry such as e.g. fcc and hcp. Polytipism is a form of polymorphism in which the different crystal structures differ only by the sequence in which 2D layers are stacked. In polytype materials, stacking order is not only hcp or fcc but takes different sequences. For SiC, there are 45 other stacking sequences in addition to hcp and fcc. The largest primitive unit cell of SiC contains 594 layers. Recently we have observed a polytypism in InP nanowires having ZB and WZ structures along the wire.