X-ray crystallography

X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of X-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. This generally leads to an understanding of the material and molecular structure of a substance. The spacings in the crystal lattice can be determined using Bragg's law. The electrons that surround the atoms, rather than the atomic nuclei themselves, are the entities which physically interact with the incoming X-ray photons. This technique is widely used in chemistry and biochemistry to determine the structures of an immense variety of molecules, including inorganic compounds, DNA and proteins. X-ray diffraction is commonly carried out using single crystals of a material, but if these are not available, microcrystalline powdered samples may also be used, although this requires different equipment and is much less straightforward.

Paper Resources/Books

• Drenth J. Principles of Protein X-Ray Crystallography. Springer-Verlag Inc. NY: 1999, ISBN 0387985875.
• Glusker JP, Lewis M, Rossi M. Crystal Structure Analysis for Chemists and Biologists. VCH Publishers. NY:1994, ISBN 0471185434.
• Rhodes G. Crystallography Made Crystal Clear. Academic Press. CA: 2000, ISBN 0125870728.