Materials Data on Ba2NdCu2HgO7 by Materials Project

Abstract

Ba2NdCu2HgO7 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 5-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.59–3.06 Å. Nd3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Nd–O bond lengths are 2.48 Å. Cu+2.50+ is bonded to five O2- atoms to form distorted 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 (1.97 Å) and one longer (2.62 Å) Cu–O bond lengths. Hg2+ is bonded to six O2- atoms to form HgO6 octahedra that share corners with four equivalent HgO6 octahedra, corners with two equivalent CuO5 square pyramids, and edges with four equivalent HgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.10 Å) and four longer (2.76 Å) Hg–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+, one Cu+2.50+, and one Hg2+ atom to form distorted OBa4CuHg octahedra that share corners with five equivalent OBa4CuHg octahedra and edges with eight OBa2Hg4 octahedra. The corner-sharing octahedra tilt angles range from 0–20°. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Nd3+, and two equivalent Cu+2.50+ atoms. In the third O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Hg2+ atoms to form a mixture of edge and corner-sharing OBa2Hg4 octahedra. The corner-sharing octahedral tilt angles are 0°.