Materials Data on Ba2Ca3Tl2(CuO3)4 by Materials Project

Tl2Ba2Ca3Cu4O12 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.80–3.14 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ca–O bond lengths are 2.50 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.47 Å) and four longer (2.53 Å) Ca–O bond lengths. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.94 Å. In the second Cu2+ site, Cu2+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.94 Å. Tl3+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing TlO6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Tl–O bond distances ranging from 2.05–2.75 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ba2+ and five equivalent Tl3+ atoms to form a mixture of distorted edge and corner-sharing OBaTl5 octahedra. The corner-sharing octahedra tilt angles range from 10–44°. In the second O2- site, O2- is bonded to four Ca2+ and two equivalent Cu2+ atoms to form OCa4Cu2 octahedra that share corners with fourteen OBa2Ca2Cu2 octahedra, edges with four OBa2Ca2Cu2 octahedra, and faces with four equivalent OCa4Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the third O2- site, O2- is bonded to two equivalent Ba2+, two equivalent Ca2+, and two equivalent Cu2+ atoms to form distorted OBa2Ca2Cu2 octahedra that share corners with ten OBaTl5 octahedra, edges with three OBa2Ca2Cu2 octahedra, and faces with four equivalent OBa2Ca2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 2–67°. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Tl3+ atom.