Materials Data on Ba2Ca2Cu3HgO8 by Materials Project

Abstract

HgBa2Ca2Cu3O8 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.75 Å) and four longer (2.92 Å) Ba–O bond lengths. Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.51 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 1.95 Å. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.95 Å. Hg2+ is bonded in a linear geometry to two equivalent O2- atoms. Both Hg–O bond lengths are 2.01 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Cu2+ atoms to form a mixture of edge, face, and corner-sharing OCa4Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Hg2+ atom. 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 eight OCa4Cu2 octahedra, edges with three OCa4Cu2 octahedra, and faces with four equivalent OBa2Ca2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 1–66°.