“…[12,13,32] BeP 2 N 4 , which has recently been described, is another example with high hardness, and an even denser and harder high-pressure polymorph has been predicted. [36][37][38][39][40][41][42][43][44][45][46][47][48] With respect to the intriguing properties that can be expected (e.g., color, magnetism, electronic properties), access to transition-metal nitridophosphates remains a challenge. Besides Zn 6 P 12 N 24 , which later was proved to be the quaternary compound Zn 8 P 12 N 24 O 2 , [33,34] and Mn 2 PN 3 , which crystallizes in a wurtzite-like structure, [35] only main-group-element-containing ternary nitridophosphates have been described.…”