Difference between hexagonal close packing and cubic close packing

difference between hexagonal close packing and cubic close packing

When tetrahedral voids of the second layer are covered by the spheres of the third layer. In this case, the spheres of the third layer are exactly aligned with those of the first layer. Thus, the pattern of spheres is repeated in alternate layers. This pattern is often written as ABAB … pattern. This type of packing is called hexagonal close packing (hcp).

When octahedral voids of the second layer are covered by the spheres of the third layer. In this case, the spheres of the third layer are are not aligned with those of either the first or the second layer. This arrangement is called �C� type.This pattern of layers is often written as ABCABC … This type of packing is called cubic close packing (ccp) or face-centred cubic (fcc) close packing.