Materials Data on KBa2Bi2O9 by Materials Project
KBa2Bi2O9 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. K is bonded to twelve O atoms to form KO12 cuboctahedra that share corners with six equivalent KO12 cuboctahedra, corners with six equivalent BaO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, and faces with six equivalent BiO6 octahedra. There are six shorter (3.00 Å) and six longer (3.22 Å) K–O bond lengths. Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with three equivalent KO12 cuboctahedra, corners with nine equivalent BaO12 cuboctahedra, faces with three equivalent KO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, and faces with five equivalent BiO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.95–3.32 Å. Bi is bonded to six O atoms to form BiO6 octahedra that share corners with three equivalent BiO6 octahedra, faces with three equivalent KO12 cuboctahedra, and faces with five equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Bi–O bond lengths are 2.12 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to two equivalent K, two equivalent Ba, and two equivalent Bi atoms. In the second O site, O is bonded in a distorted single-bond geometry to one K, three equivalent Ba, and one Bi atom.