The symmetry of crystalline layers and multilayers is described by the diperiodic groups. Their irreducible representations are classified and tabulated. On this basis some physical properties are investigated.

BREAKDOWN of the Jahn-Teller theorem is predicted for few structures only.
CuOconducting plane of HTS compounds is among them.
_{2} |

Computer implementation of diperiodic symmetry is developping (program for the irreducible representations is available).

References:

Vibronic (In)Stability for Mono- and Di- periodic Systems,

VI International Conference on

Ascona, Switzerland, (1996) 26.

The Breakdown of the Jahn-Teller Theorem in

Irreducible Representations of Diperiodic Groups (pdf 328 KB)

Electron-phonon Coupling Reduction in Tetragonal and Hexagonal Layers, 2D Conductivity in Surface States and Monolayers, 5-8 March 2001, Bad Honnef, Germany

B. Nikolic, M.Sci Thesis

Vibronska (ne)stabilnost diperiodicnih sistema (pdf 616 KB)