It is the number of lattice points touching one lattice point in a crystalline solid. For example in case of Sodium chloride it is 6 .
1. Co-ordination number Number of spheres touching one Sphere in a close packed structure is called co-ordination number of a lattice 2. Unit cell The smallest repeating pattern in a crystal lattice is called a unit cell. Characteristics of unit cell Are unit cell has a characteristic dimensions along the three edges a,b,c and interfacial