Projective Representations Construction for Different Points of Brillouin Zone. Application for Space Symmetry Groups $P{4}_1{2}_{1}2$ and $P{4}_3{2}_{1}2$

Abstract

It was suggested method of constructing of irreducible projective representations in different points of Brilluin zone. Points Γ, Λ, Z, S, A, Σ, M, V, R, and X of space symmetry groups $P{4}_1{2}_{1}2$ and $P{4}_3{2}_{1}2$ were examined. At each of these points one- and two-valued irreducible projective representations of wave vector groups were constructed for two enantiomorphous modifications. Influence of time inversion at these points also was taken into consideration by means of Herring criterion.

10 pages, 2 figures