All symbols in the SiC structures have a particular this means: The number 3 in 3C-SiC refers to the 3-bilayer periodicity with the stacking (ABC) and the letter C denotes the cubic symmetry in the crystal. 3C-SiC is the one feasible cubic polytype. The wurtzite ABAB. Other uses are in https://waylonakudl.blazingblog.com/35796958/the-smart-trick-of-silica-aerogel-that-no-one-is-discussing