  It was suggested method of constructing of irreducible projective
representations in different points of Brilluin zone. Points \Gamma, \Lambda,
Z, S, A, \Sigma, M, V, R, and X of space symmetry groups $P4_{1}2_{1}2$ and
$P4_{3}2_{1}2$ 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.

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