Synthesis and Crystal Structure of the New Quaternary Subnitride Na 15 Li 8 Ba 12 N 6

The crystal structure of the new compound Na 15 Li 8 Ba 12 N 6 has been determined from single‐crystal X‐ray diffraction data. It crystallizes in the trigonal system, space group $R{\bar 3}m$ with a = 12.3409(9) Å, c = 33.311(4) Å, Z = 3, and R 1 = 0.037 ( wR 2 = 0.046) for 1912 reflections with I o >2σ( I o ). The structure can be described as an fcc‐type packing of Na tetrahedrons with Li 8 Ba 12 N 6 clusters and centered Na hexagons in chair conformation among them. These hexagons together with some tetrahedral vertices connect to parallel infinite layers. By analogy with quaternary Na/Ba/Ca subnitrides this structure can be also regarded as a “salt in metal”.