The template tet-C 4 (space group I-4m2, No. 119) is characterized by two 2-fold Wyckoff atomic positions for carbon as shown in Table . The tetragonal body-centered structure in Fig. shows the corresponding carbon atoms labeled C1 (brown spheres) at the origin and body center and C2 (white spheres) forming tetrahedra around C1. Considering the structure in the simple tetragonal configuration, the second column of Table explains the four carbon sites. The transformation to C 5 retains the tetragonal symmetry, albeit lowered from body-centered ("I" centering) to primitive ("P" centering) and resolved in space group P-4m2, No. 115. This consists in keeping the body-centered carbon (C1 at ½, ½, ½) so that it becomes in C(1c) Wyckoff position -follow the transformation arrows -as well as the two C2s (C2a and C2b) become C3(2g) where the z coordinate becomes zʹ instead of ¼. The additional carbon C2 is provided by parameterizing the z position of C1b, resulting in a two-fold C2 (2e) at 0, 0, z.