Fig. 6.

Simple illustration of the preference for like second-nearest-neighbour rotations arising from a preference for unlike adjacent rotations, as described in the text, and leading to the superlattice. Second-nearest neighbour sites are shown at the left and right, and the vertices of the two associated elementary triangles above and below. The four configurations as described in the text are shown, and the number of undesirable interactions for each is shown on the right