The present work focused on the identification of a viable structure of equiatomic SiCN following a protocol involving crystal chemistry rationalization of structures submitted in a second step to unconstrained geometry optimization with DFT-based quantum mechanical calculations. Among different hypotheses, the most stable structure consists of SiC 2 N 2 tetrahedra with a stacking resembling tetragonal "glitter" C 6 and the "glitter"-derived silicon dicarbide. Confirmation of the stabilities for "glitter" C 6 , silicon dicarbide and SiCN were inferred from the cohesive energies. The mechanical (elastic properties) and dynamic (phonon dispersions) stabilities have been confirmed.