The geometrical basis of crystal chemistry. Part 2

A procedure for the systematic derivation of three-dimensional 4-connected nets is outlined and applied to nets with 2, 3 and 4 points in the repeat unit. The relevance to crystal chemistry of nets containing loops (digons) is noted. Some of the simplest open packings of tetrahedra are indicated, and a number of more complex nets (4-, 5-, 6-, 8-and 12-connected) with cubic symmetry are listed.