Materials Data on Ba2GdCu2(HgO4)2 by Materials Project
Ba2GdCu2(HgO4)2 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 2.68–3.00 Å. Gd3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Gd–O bond lengths are 2.45 Å. Cu+2.50+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one HgO6 octahedra and corners with four equivalent CuO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.96 Å) and one longer (2.46 Å) Cu–O bond lengths. Hg2+ is bonded to six O2- atoms to form distorted HgO6 octahedra that share corners with four equivalent HgO6 octahedra, a cornercorner with one CuO5 square pyramid, and edges with eight equivalent HgO6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are a spread of Hg–O bond distances ranging from 2.08–2.77 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Gd3+, and two equivalent Cu+2.50+ atoms. In the second O2- site, O2- is bonded to one Ba2+ and five equivalent Hg2+ atoms to form a mixture of distorted edge and corner-sharing OBaHg5 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the third O2- site, O2- is bonded to four equivalent Ba2+, one Cu+2.50+, and one Hg2+ atom to form a mixture of distorted edge and corner-sharing OBa4CuHg octahedra. The corner-sharing octahedra tilt angles range from 0–16°.