Materials Data on BaTmCo4O7 by Materials Project
BaTmCo4O7 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Ba2+ is bonded in a 3-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.85–3.20 Å. Tm3+ is bonded to six O2- atoms to form TmO6 octahedra that share corners with twelve CoO4 tetrahedra. There are a spread of Tm–O bond distances ranging from 2.20–2.31 Å. There are four inequivalent Co+2.25+ sites. In the first Co+2.25+ site, Co+2.25+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three equivalent TmO6 octahedra and corners with six CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–60°. There are a spread of Co–O bond distances ranging from 1.94–2.00 Å. In the second Co+2.25+ site, Co+2.25+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three equivalent TmO6 octahedra and corners with six CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Co–O bond distances ranging from 1.94–2.00 Å. In the third Co+2.25+ site, Co+2.25+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three equivalent TmO6 octahedra and corners with six CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Co–O bond distances ranging from 1.94–1.99 Å. In the fourth Co+2.25+ site, Co+2.25+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with three equivalent TmO6 octahedra and corners with six CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Co–O bond distances ranging from 1.87–1.94 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Tm3+, and two Co+2.25+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Tm3+, and two Co+2.25+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+, one Tm3+, and two Co+2.25+ atoms. In the fourth O2- site, O2- is bonded in a tetrahedral geometry to four Co+2.25+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Tm3+, and two Co+2.25+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Tm3+, and two Co+2.25+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Tm3+, and two Co+2.25+ atoms.