0.22 ) 4 O]Bi 2 (I) and [(Ba0.62Sr0.38)10N2O]Bi4 (II) are grown from melts of Ba, Sr, and Bi (N2 atmosphere that contains small amounts of O2, 1123 K). Both compounds crystallize in the tetragonal space group I4/mmm with Z = 2. (I) adopts the K2NiF4 structure type with layers of vertex-sharing (Ba,Sr)4Ba2O octahedra. (II) is isotypic with Sr4Ti3O10 and contains slabs of three layers of vertex-sharing octahedra further connected via corners. The compounds are members of an inverse Ruddlesden-Popper series of general formula (A3n+1ONn-1)Bin+1 with n = 1, 3. -(GAEBLER, F.; PROTS, V.; NIEWA*, R.; Z. Anorg. Allg. Chem. 633 (2007) 1, 93-97; Dep. Chem., TU Muenchen, D-85747 Garching, Germany; Eng.) -Schramke 09-003