“…Combinations of Ge II /N usually form bent [Ge II N 2 ] 4– units, e.g., in Ca 2 GeN 2 . Ge III in nitrides is found in [Ge 2 N 6 ] 12– units with a Ge–Ge bond, e.g., in Ca 6 [Ge 2 N 6 ], while combinations of Ge IV /N most commonly form [Ge IV N 4 ] 8– tetrahedra, analogous to nitridophosphates . The tetrahedra can be found isolated (e.g., in Sr 4 GeN 4 ), connected by shared vertices (e.g., in Ca 5 Ge 2 N 6 ) or edges (e.g., in Sr 5 Ge 2 N 6 ) or condensed to a 3D-network (e.g., in CaGeN 2 ). ,− Rarely, also trigonal planar [Ge IV N 3 ] 5– units (e.g., in Ba 9 (GeN 3 ) 3 N) were observed .…”