X-ray crystallography


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.

X-ray crystallography,

the study of crystal structures through X-ray diffraction techniques. When an X-ray beam bombards a crystalline lattice in a given orientation, the beam is scattered in a definite manner characterized by the atomic structure of the lattice. This phenomenon, known as X-ray diffraction, occurs when the wavelength of X-rays and the interatomic distances in the lattice have the same order of magnitude. In 1912, the German scientist Max von Laue predicted that crystals exhibit diffraction qualities. Concurrently, W. Friedrich and P. Knipping created the first photographic diffraction patterns. A year later Lawrence Bragg successfully analyzed the crystalline structures of potassium chloride and sodium chloride using X-ray crystallography, and developed a rudimentary treatment for X-ray/crystal interaction (Bragg's Law). Bragg's research provided a method to determine a number of simple crystal structures for the next 50 years. In the 1960s, the capabilities of X-ray crystallography were greatly improved by the incorporation of computer technology. Modern X-ray crystallography provides the most powerful and accurate method for determining single-crystal structures. Structures containing 100–200 atoms now can be analyzed on the order of 1–2 days, whereas before the 1960s a 20-atom structure required 1–2 years for analysis. Through X-ray crystallography the chemical structure of thousands of organic, inorganic, organometallic, and biological compounds are determined every year.

Bibliography

See M. Buerger, X-Ray Crystallography (1980).

X-ray crystallography

The study of crystal structure by x-ray diffraction techniques. For the experimental aspects of x-ray diffraction See X-ray diffraction

Structurally, a crystal is a three-dimensional periodic arrangement in space of atoms, groups of atoms, or molecules. If the periodicity of this pattern extends throughout a given piece of material, one speaks of a single crystal. The exact structure of any given crystal is determined if the locations of all atoms making up the three-dimensional periodic pattern called the unit cell are known. The very close and periodic arrangement of the atoms in a crystal permits it to act as a diffraction grating for x-rays. See Crystallography

x-ray crystallography

[′eks ‚rā ‚krist·əl′äg·rə·fē]
(crystallography)
The study of crystal structure by x-ray diffraction techniques. Also known as roentgen diffractometry.
References in periodicals archive ?
Jackson et al., "Watching a protein as it functions with 150-ps time-resolved X-ray crystallography, "Science, vol.
The Crystal Farm family of products with its integrated crystal incubation and imaging capabilities complements Bruker AXS's line of X-ray crystallography products for structural proteomics applications.
* The role of X-ray crystallography in medicine: discuss the current use of X-ray crystallography, specifically in medicine, building on the crystallography activities published in previous issues of this journal throughout 2014.
Wilson's laboratory used X-ray crystallography to determine the atomic structures of the H7N9 hemagglutinin protein bound to these sialic acid receptor molecules.
Researchers used X-ray crystallography, a technique in which X-rays are shot at crystallized molecules to determine the molecules' shape and structure, to show what the receptor looks like in atomic detail when it is bound to neurotensin.
Their topics include producing and purifying viruses for structural studies, the X-ray crystallography of virus capsids, the evolution of viral capsid structures, mechanisms of icosahedral virus assembly, attachment and entry, developing anti-HIV drugs, and viral vectors for gene delivery.
In contrast, with X-ray crystallography (the conventional technique for atomic resolution models of biological structures), researchers grow crystal structures replicating the sample and then use diffraction to solve the crystal structure.
Dr Towns-Andrews trained as a chemist and graduated with a PhD in x-ray crystallography.
Expert contributors discuss such topics as a comparison of nonlinear optical spectroscopy with x-ray crystallography, the use of multiphoton fluorescence to study chemical phenomenon on the skin and multi-modal approaches that use several spectroscopic techniques in a single instrument.
Single crystal x-ray crystallography complements Varian's NMR business, especially in the area of drug discovery and allows it to offer a product line that its rival in the NMR market, Bruker, also provides.
Traditional x-ray systems for 3-D structure determination are floor-standing, require significant infrastructure, and typically are installed in specialist x-ray crystallography centers.
The answer lies in the development of x-ray crystallography more than a century later in 1912.