Figure 14.

The hypergraph of correlations corresponding to the rectangular unit cell of the double hcb layer with Z = 4. In blue and red, hyperedges relative, respectively, to the 10 and 01 directions; in white, orange and green, vertices representing configurations equivalent to Figs. 11 ▸(a), 11 ▸(b) and 11 ▸(c), respectively.