Materials Data on BaTl2O4 by Materials Project
Tl2BaO4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–3.13 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted trigonal planar geometry to three O2- atoms. All Ba–O bond lengths are 2.62 Å. There are three inequivalent Tl3+ sites. In the first Tl3+ site, Tl3+ is bonded to six O2- atoms to form a mixture of face and corner-sharing TlO6 octahedra. The corner-sharing octahedra tilt angles range from 23–30°. There are a spread of Tl–O bond distances ranging from 2.21–2.45 Å. In the second Tl3+ site, Tl3+ is bonded to six O2- atoms to form a mixture of distorted face, edge, and corner-sharing TlO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Tl–O bond distances ranging from 2.23–2.43 Å. In the third Tl3+ site, Tl3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Tl–O bond distances ranging from 2.19–2.78 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to four Tl3+ atoms to form distorted OTl4 trigonal pyramids that share corners with four equivalent OBaTl3 tetrahedra and edges with two equivalent OTl4 trigonal pyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Tl3+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Ba2+ and two equivalent Tl3+ atoms. In the fourth O2- site, O2- is bonded to one Ba2+ and three Tl3+ atoms to form distorted corner-sharing OBaTl3 tetrahedra. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to one Ba2+ and three Tl3+ atoms. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Ba2+ and two equivalent Tl3+ atoms. In the seventh O2- site, O2- is bonded in a square co-planar geometry to four Tl3+ atoms.