Figure 1
(a) A stereographic projection of the symmetry elements of point group type 321. The three hexagonal axes A1, A2 and A3 in the plane perpendicular to the unique axis are shown. (b) A stereographic projection of the two forms {10.2} and {11.1} in the point group 321, with the corresponding Bravais–Miller indices of the faces. The permutation of indices h, k and i emphasizes the equivalence of these faces in the group. (c) The same as in panel (b) but with Miller indices only. The equivalence of the faces is less evident. |