A non-mathematical introduction to the superspace description of modulated structures

Title data

Wagner, Trixie ; Schönleber, Andreas:
A non-mathematical introduction to the superspace description of modulated structures.
In: Acta Crystallographica Section B. Vol. 65 (2009) Issue 3 . - pp. 249-268.
ISSN 2052-5206
DOI: https://doi.org/10.1107/S0108768109015614

Official URL:

Abstract in another language

The X-ray analysis of (6R,7aS)-6-(tert-butyl-dimethylsilanyloxy)-1-hydroxy-2-phenyl-5,6,7,7a-tetrahydropyrrolizin-3-one, C₁₉H₂₇NO₃Si, revealed a diffraction pattern which is typical for modulated structures: strong Bragg peaks surrounded by weaker reflections which cannot be indexed with the same three reciprocal lattice vectors that are used to describe the strong peaks. For this class of crystal structures the concept of superspace has been developed which, however, for many crystallographers still constitutes a Gordian Knot. As a possible tool to cut this knot the crystal structure of the above-mentioned tetrahydropyrrolizinone derivative is presented as an illustrative example for handling and describing the modulated structure of a typical pharmaceutical (i.e. molecular) compound. Having established a working knowledge of the concepts and terminology of the superspace approach a concise and detailed description of the complete process of peak indexing, data processing, structure solution and structure interpretation is presented for the incommensurately modulated crystal structure of the above-mentioned compound. The superspace symmetry applied is P2₁(α0γ)0; the (incommensurate) q vector components at 100K are α = 0.1422(2) and γ = 0.3839(8).

Further data

Item Type:	Article in a journal
Refereed:	Yes
Keywords:	molecular compound; incommensurately modulated structure; superspace; teaching
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography > Chair Crystallography - Univ.-Prof. Dr. Sander van Smaalen Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	10 Aug 2015 10:22
Last Modified:	27 Jan 2023 08:24
URI:	https://eref.uni-bayreuth.de/id/eprint/17851