Abstract
TWINNING of crystals often results in the superposition of reciprocal lattice points and the appearance of a pseudo-lattice. In many cases this can be recognized from the diffraction data by the presence of systematic absences inconsistent with those absences expected from space-group symmetry. Because of the superposition of much of the diffraction data, exact intensities for each reciprocal lattice point cannot be obtained. If it is assumed that the twinning is on a gross enough scale, then the intensities of the superimposed reflexions will be proportional to the sum of the F2 of the individual reciprocal lattice points comprising the reflexion, without regard to their relative phases. Thus it is not possible to apply the accepted Fourier methods of crystal structure determination in the usual way. In the case of contact twins a physical separation can be made, and single-crystal data can be obtained; but in the event of fine polysynthetic twinning or the ‘anti-phase domain’ type of twinning usually resulting from cooling through a phase change, one is forced to work with the twinned material.
Similar content being viewed by others
Article PDF
References
Buerger, M. J., Acta Cryst., 4, 531 (1951).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
FRUEH, A. Fourier Projections of Twinned Crystals. Nature 193, 1172 (1962). https://doi.org/10.1038/1931172b0
Issue Date:
DOI: https://doi.org/10.1038/1931172b0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.