Materials Data on Ba2CaTl2(CuO4)2 by Materials Project

Abstract

Tl2Ba2CaCu2O8 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.78 Å) and four longer (2.93 Å) Ba–O bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.78 Å) and four longer (2.93 Å) Ba–O bond lengths. 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 2.53 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ca–O bond lengths are 2.53 Å. 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 1.98 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 1.98 Å. There are two inequivalent Tl3+ sites. In the first Tl3+ site, Tl3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are one shorter (2.11 Å) and four longer (2.28 Å) Tl–O bond lengths. In the second Tl3+ site, Tl3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are one shorter (2.11 Å) and four longer (2.28 Å) Tl–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ba2+, two equivalent Ca2+, and two equivalent Cu2+ atoms to form a mixture of distorted corner, edge, and face-sharing OBa2Ca2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Tl3+ atom. In the third O2- site, O2- is bonded to two equivalent Ba2+, two equivalent Ca2+, and two equivalent Cu2+ atoms to form a mixture of distorted corner, edge, and face-sharing OBa2Ca2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the fourth O2- site, O2- is bonded to four Tl3+ atoms to form a mixture of corner and edge-sharing OTl4 tetrahedra. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Tl3+ atom.