Nitridic Analogs of Micas AESi(3)P(4)N(10)(NH)(2) (AE=Mg, Mg(0.94)Ca(0.06), Ca, Sr)

We present the first nitridic analogs of micas, namely AESi(3)P(4)N(10)(NH)(2) (AE=Mg, Mg(0.94)Ca(0.06), Ca, Sr), which were synthesized under high‐pressure high‐temperature conditions at 1400 °C and 8 GPa from the refractory nitrides P(3)N(5) and Si(3)N(4), the respective alkaline earth amides, implementing NH(4)F as a mineralizer. The crystal structure was elucidated by single‐crystal diffraction with microfocused synchrotron radiation, energy‐dispersive X‐ray spectroscopic (EDX) mapping with atomic resolution, powder X‐ray diffraction, and solid‐state NMR. The structures consist of typical tetrahedra–octahedra–tetrahedra (T‐O‐T) layers with P occupying T and Si occupying O layers, realizing the rare motif of sixfold coordinated silicon atoms in nitrides. The presence of H, as an imide group forming the SiN(4)(NH)(2) octahedra, is confirmed by SCXRD, MAS‐NMR, and IR spectroscopy. Eu(2+)‐doped samples show tunable narrow‐band emission from deep blue to cyan (451–492 nm).