Structure of Some Ionic Compounds
Basic Concepts of Chemical Crystallography
CHEMICAL CRYSTALLOGRAPHY- A branch of physical science that deals with the study of crystals i.e. their source, classification, properties and structure etc. is called chemical crystallography. A crystalline solid consist of a large number of small units called crystal. A crystal is a solid figure with a definite geometrical shape, flat faces and sharp edges. Crystal lattice and unit cell- “Regular arrangement of constituent particles i.e. atoms, ions or molecules of a crystal in a three dimensional space is called crystal lattice or space lattice.” “The smallest three dimensional portion of a complete space lattice which when repeated over and again in different directions to generate the complete space lattice is called the unit cell” The situation may be compared with that of a thick wall made up of bricks, where brick is similar to the unit cell and the wall to the complete space lattice. The unit cell may be considere...
