Gähler, Franz2009-10-012016-03-312009-10-012016-03-311988317895494http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-46624http://elib.uni-stuttgart.de/handle/11682/7064http://dx.doi.org/10.18419/opus-7047A detailed model structure of dodecagonal quasicrystals is proposed which applies to both dodecagonal Ni-Cr and V-Ni or V-Si-Ni. This model structure can be represented as the restriction of a 5d periodic structure to a 3d subspace, which is identified with physical space. The point group and the space group of the 5d periodic structure are determined. The latter is non-symmorphic, containing a set of glide "planes" and a screw axis. These space group elements lead to characteristic extinctions in the Fourier spectrum, which should be experimentally observable. A numeric calculation, which includes multiple scattering effects for electron diffraction, confirms the presence of the extinctions predicted by the space group analysis. The model structure proposed here serves as a very instructive example how crystallographic concepts, such as Bravais type, point group, or space group, can be applied to quasicrystals.eninfo:eu-repo/semantics/openAccessQuasikristall , Kristallstruktur530conferenceObject2010-02-02