Abstract
The ideas of little groups and orbits of a group action as reviewed by Michel are used for a reexamination of Birman's subduction criterion and Ascher's discussion of the inverse Landau problem. As an illustration of the ease of application of these concepts from differential geometry we present a classification of the subgroups of that result from distortions with symmetries of a single wave vector from one of the irreducible representations at the , , , or point. These are the representations that are important in commensurate structural phase transitions.
- Received 17 September 1981
DOI:https://doi.org/10.1103/PhysRevB.25.1813
©1982 American Physical Society