IntroductionCrystalline and Amorphous SolidsPolymorphism and AllotropyMitcherlich′s Law of IsomorphismClassification of Crystalline SolidSpace Lattice and Unit CellCrystal SystemsEffective Number of Atoms Per Cubic Unit CellVoids or Interstitial SiteCoordination NumberEffect of Temperature and Pressure on Coordination NumbersDensityDefects in SolidsNon-stoichiometric DefectsElectrical Properties of SolidsCrystal Planes and Miller IndicesX-Ray Diffraction and Bragg’s Equation