In
X-ray crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...
, crystallographic disorder describes the
cocrystallization of more than one
rotamer,
conformer, or
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
Is ...
where the center of mass of each form is identical or unresolvable. As a consequence of disorder, the crystallographic solution is the sum of the various forms. In many cases, the components of the disorder are equally abundant, and, in other cases, the weighting coefficients for each component differ. Disorder can entail a pair or several components. Disorder usually arises when the forms are nearly equal in energy and the crystal lattice is sufficiently spacious to accommodate the various components.
File:DOSBIW.png, Structure of Mo(CH3)5 showing 4-fold disorder of one methyl group.[{{cite journal, journal=Chemical Communications, issue=12, title=Pentamethylmolybdenum, authors=Beatrice Roessler, Sven Kleinhenza, Konrad Seppelt, doi=10.1039/b000987n, year=2000, pages=1039–1040]
File:DOSBIWoneRotamer.png, One of four rotamers of Mo(CH3)5.
References
Crystallography
Materials science
Protein structure
Protein methods
Protein imaging
Synchrotron-related techniques