DOI: 10.17188/1745610
title: Materials Data on Ba4In2O7 by Materials Project

description: Ba4In2O7 crystallizes in the tetragonal I4mm space group. The structure is two-dimensional and consists of two Ba4In2O7 sheets oriented in the (0, 0, 1) direction. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to five O2- atoms to form distorted BaO5 square pyramids that share a cornercorner with one InO6 octahedra, corners with four equivalent BaO5 square pyramids, corners with four equivalent InO5 trigonal bipyramids, and edges with four equivalent BaO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.37 Å) and four longer (2.99 Å) Ba–O bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.82–3.02 Å. In the third Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. All Ba–O bond lengths are 2.58 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.80 Å) and four longer (3.05 Å) Ba–O bond lengths. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to five O2- atoms to form distorted InO5 trigonal bipyramids that share corners with four equivalent BaO5 square pyramids and corners with four equivalent InO5 trigonal bipyramids. There are one shorter (2.07 Å) and four longer (2.22 Å) In–O bond lengths. In the second In3+ site, In3+ is bonded to six O2- atoms to form InO6 octahedra that share corners with four equivalent InO6 octahedra and a cornercorner with one BaO5 square pyramid. The corner-sharing octahedral tilt angles are 3°. There are a spread of In–O bond distances ranging from 2.12–2.38 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ba2+ and two equivalent In3+ atoms to form distorted OBa2In2 tetrahedra that share corners with two equivalent OBa5In octahedra, corners with four equivalent OBa2In2 tetrahedra, and edges with four equivalent OBa2In2 tetrahedra. The corner-sharing octahedral tilt angles are 73°. In the second O2- site, O2- is bonded to four Ba2+ and two equivalent In3+ atoms to form distorted OBa4In2 octahedra that share corners with eight OBa5In octahedra, corners with four equivalent OBa4In square pyramids, edges with two equivalent OBa4In2 octahedra, faces with six OBa5In octahedra, and faces with two equivalent OBa4In square pyramids. The corner-sharing octahedra tilt angles range from 3–51°. In the third O2- site, O2- is bonded to five Ba2+ and one In3+ atom to form OBa5In octahedra that share corners with eight OBa5In octahedra, corners with four equivalent OBa2In2 tetrahedra, and edges with eight OBa5In octahedra. The corner-sharing octahedra tilt angles range from 3–49°. In the fourth O2- site, O2- is bonded to five Ba2+ and one In3+ atom to form distorted OBa5In octahedra that share corners with twelve OBa5In octahedra, a cornercorner with one OBa4In square pyramid, edges with eight OBa5In octahedra, and faces with four equivalent OBa4In2 octahedra. The corner-sharing octahedra tilt angles range from 17–51°. In the fifth O2- site, O2- is bonded to four equivalent Ba2+ and one In3+ atom to form distorted OBa4In square pyramids that share corners with nine OBa5In octahedra, corners with four equivalent OBa4In square pyramids, edges with four equivalent OBa4In square pyramids, and faces with four equivalent OBa4In2 octahedra. The corner-sharing octahedra tilt angles range from 0–50°.