Materials Data on KBa2Bi2O7 by Materials Project

Abstract

KBa2Bi2O7 crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. K is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 2.72–3.10 Å. There are two inequivalent Ba sites. In the first Ba site, Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight BiO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.89–3.15 Å. In the second Ba site, Ba is bonded in a 1-coordinate geometry to nine O atoms. There are a spread of Ba–O bond distances ranging from 2.54–3.09 Å. There are two inequivalent Bi sites. In the first Bi site, Bi is bonded to six O atoms to form BiO6 octahedra that share corners with five BiO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Bi–O bond distances ranging from 2.12–2.19 Å. In the second Bi site, Bi is bonded to six O atoms to form BiO6 octahedra that share corners with five BiO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Bi–O bond distances ranging from 2.09–2.31 Å. There are five inequivalent O sites. In the first O site, O is bonded to one K, four equivalent Ba, and one Bi atom to form distorted OKBa4Bi octahedra that share corners with seventeen OBa4Bi2 octahedra, edges with eight OKBa4Bi octahedra, and faces with four equivalent OBa4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 0–58°. In the second O site, O is bonded to four equivalent K, one Ba, and one Bi atom to form distorted OK4BaBi octahedra that share corners with seventeen OBa4Bi2 octahedra, edges with eight OKBa4Bi octahedra, and faces with four equivalent OK2Ba2Bi2 octahedra. The corner-sharing octahedra tilt angles range from 0–56°. In the third O site, O is bonded to four Ba and two equivalent Bi atoms to form distorted OBa4Bi2 octahedra that share corners with eighteen OKBa4Bi octahedra, edges with three OBa4Bi2 octahedra, and faces with eight OBa4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 1–62°. In the fourth O site, O is bonded to two equivalent K, two equivalent Ba, and two equivalent Bi atoms to form distorted OK2Ba2Bi2 octahedra that share corners with eighteen OKBa4Bi octahedra, edges with three OBa4Bi2 octahedra, and faces with eight OBa4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 5–62°. In the fifth O site, O is bonded to four equivalent Ba and two Bi atoms to form distorted OBa4Bi2 octahedra that share corners with twenty-two OKBa4Bi octahedra, edges with four equivalent OBa4Bi2 octahedra, and faces with eight OBa4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 0–62°.