Dichromatic symmetry

However, by introducing the anti-mirror reflection (m') operation the full dihedral D3 symmetry is restored.

In 1930 Heinrich Heesch was the first person to formally postulate an antisymmetry operation in the context of examining the 3D space groups in 4D.

[13] Heesch's work was influenced by Weber's 1929 paper on black-and-white colouring of 2D bands.

Woods published a series of four papers with the title The geometrical basis of pattern design.

The last of these[15] was devoted to counterchange symmetry and in which was derived for the first time the 46 dichromatic 2D point groups.

The work of Heesch and Woods were not influential at the time, and the subject of dichromatic symmetry did not start to become important until the publication of A.V.

Thereafter the subject developed rapidly, initially in Russia but subsequently in many other countries, because of its importance in magnetic structures and other physical fields.