ABSTRACT
Crystallography is the study of molecular and crystalline structure and their properties. Crystals exhibit symmetry such as rotation axes and glides and can be classified into 32 point groups and 230 space groups. Mathematical applications of the reciprocal lattice give straightforward calculations of the Bragg d-spacings and the interfacial angles of the crystal. The usage of the terms triclinic, monoclinic, orthorhombic, tetragonal and cubic is consistent for crystal systems, Bravais lattices and crystal families. Use of the reciprocal lattice unifies and simplifies crystallographic calculations. The motivation for the reciprocal lattice is that the X-ray pattern can be interpreted as the reciprocal lattice with the X-ray diffraction intensities superimposed on it. The Crystallographic Information File (CIF) format is used for distributing crystallographic information. The protein crystal is precipitated from a supersaturated solution of the macromolecule in which the protein is partitioned between the solid phase and the solution.
