The understanding of the electronic picture of the materials used in electronics industry is an utmost important thing for their effective use in practice. Various tools are used for the purpose and one among them is the X-ray diffraction technique. X-ray diffraction technique provides the finite details of the materials in the form of charge density picture. Charge density picture can be analyzed qualitatively and quantitatively for the type of bonding existing in solids and also for the measure of the charges involved in deciding the physical and chemical properties of the chosen system. And hence, the study on charge density using experimental X-ray diffraction information is inevitable for the better understand and the utility of the material. This monograph elaborately deals with the charge density distribution study on some of the ionic and fluoride solids and some technologically important semiconductor materials.