Eur. Phys. J. B 2, 191-196 (1998)
https://doi.org/10.1007/s100510050240

Line group theory of commensurate and incommensurate modulations

¹ Department for Low Temperature Physics, Eötvös University, 1088 Budapest, Hungary
² Department of Physics and Process Control, Gödöllö University of Agricultural Sciences, 2103 Gödöllö, Hungary
³ Wihuri Physical Laboratory, University of Turku, 20500 Turku, Finland

Received: 20 July 1997
Accepted: 25 August 1997
Published online: 15 March 1998

Abstract

It is shown that the line group formalism proposed is suitable to describe both commensurate and incommensurate modulations. Symmetry groups of modulated crystal lattices can completely be characterized by symmetry transformations existing in real space, without any application of the formalism based on reciprocal space. As typical examples of the method elaborated, the fundamental invariance and symmetry properties of spin density functions and the soliton lattice are determined.