“…Crystal structure prediction calculations of pure Ni performed earlier by similar procedure showed its stability in Fm 3̄ m ( fcc ) structure up to 400 GPa. 36,37 For pure boron, carbon, and nitrogen the following data have been used: B- R 3̄ m , - Pnnm , - Cmca , and - P 6 3 / mcm ; 38 C- P 6 3 mc (graphite) and - Fd 3̄ m (diamond); N- Pa 3̄, - I 2 1 3, 39 , - Pba 2, 40 and - I 4̄3 m . 41 The pressures of phase transition between listed polymorphic modifications are shown in Fig.…”