Nonerystallographic symmetry and the sampling theorem

Abstract

When the asymmetric unit of a crystal structure expresses some nonerystallographic symmetry it is often found that these local symmetry elements involve only proper rotations. Under these conditions the relations between the structure factors resulting from this repetition within the crystallographic asymmetric unit reduce to a statement of the Whittaker-Shannon, sampling theorem, and thereby suggest the real space method for solution. A simple model structure is solved as an example. © 1974, Walter de Gruyter. All rights reserved.