Glide reflection plane

Figure 2 (a) The polyphenantrene polymer with its glide-reflection plane. Here the A and B sublattices are invariant under this symmetry operation, (b) Polyaceacene polymer with its glide-reflection plane. Notice that here the A and B sublattices transform one into each other under this symmetry operation. 

Figure 8-1. Planar decoration with two-dimensional space group after Budden [4], (a) The decoration (b) Symmetry elements of the pattern (c) Some of the glide reflection planes and their effects in the pattern.

Among the projected symmetry elements in Figure 9-22c, there are some which are derived from the generating elements. This is the case, for example, for vertical glide-reflection planes with elementary translations all and bll (represented by broken lines), translations (dot-dash lines), vertical screw axes 2, and 42, and symmetry centers (small hollow circles, some of which lie above the plane by 1/4 of the elementary translation). 

Fm3m by replacing the symmetry planes m by glide-reflection planes d with the latter displaced i along the cube edges. 

Fig. 1. (a) 2D motif possessing the non-symmorphic plane group symmetry p2mg. The relative positions of the mirror plane m, the glide reflection plane g, and the inversion i are shown (b) The corresponding rectangular first BZ is presented, where k (quasimomenta) points of the type X, Z and Y are marked. 

Pc P and J are inverted downward and then shifted by c/2 along z by the horizontal glide reflection plane c (thin dashed line) in the jc-z plane this induces a set of new glide planes parallel to the first set and running along the cell edges. 

A new type of glide-reflection plane appears in the C-setting therefore the symbol is somewhat ambiguous. ... 

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