Crystal is a three dimensional periodic array of atoms. Crystal lattice is the geometrical pattern of the crystal, where all the atom sites are represented by the geometrical points. There are two cla...Crystal is a three dimensional periodic array of atoms. Crystal lattice is the geometrical pattern of the crystal, where all the atom sites are represented by the geometrical points. There are two classes of crystal lattices. When all of the lattice points are equivalent, it is called Bravais lattice. Otherwise, it is called non-Bravais lattice. The non-Bravais lattice may be regarded as a combination of two or more interpenetrating Bravais lattices with fixed orientations relative to each other
