Twinning by reticular merohedry

Maclage par mériédrie réticulaire (Fr). Geminazione per meroedria reticolare(It)

Twinning by reticular merohedry

In the presence of a sublattice displaying symmetry other than that of the crystal lattice, a symmetry element belonging to the sublattice point group but not to the crystal point group can act as twinning operator. If lattice and sublattice have the same point group but (some of) their elements of symmetry are differently oriented twinning by polyholohedry can form.