ABSTRACT
A crystalline solid is composed of one or more crystals with a well-defined ordered structure in three dimensions. A unit cell is the smallest box-like unit from which can imagine constructing a crystal by stacking the units in three dimensions. Different lattice types are possible within each of the crystal systems since the lattice points within the unit cell may be arranged in different ways. There is the primitive or simple cubic cell, the face centered cell, body centered cell and the end or base centered cell. When a crystal lattice forms the ions are arranged in the most efficient way of packing spheres into the smallest possible space. In any close-packed structure, each atom is surrounded by other atoms. The number of nearest neighbors is called the coordination number.
