It should be noted that for boron nitride mainly sp 2 -bonded polytypes are known, which are characterized by different layer stacking sequences (e.g. AA'AA' for hexagonal BN, ABCABC for rhombohedral BN, etc.) . In our work results on new hexagonal sp 3 -bonded BN polytypes and BC 2 N with cfc topology are presented. The studies of the structures of the new phases based on crystallochemical "engineering" are supported by data on their stability, mechanical and dynamic properties, and structure of electronic bands, all calculated in the quantum mechanics framework of the Density Functional Theory (DFT) .