Materials Data on Ba2Ca2TbTi3(CuO7)2 by Materials Project

Abstract

Ba2Ca2TbTi3(CuO7)2 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, corners with four equivalent CaO12 cuboctahedra, a faceface with one CaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, faces with four equivalent TiO6 octahedra, and faces with four equivalent CuO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.77–3.09 Å. Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, corners with eight equivalent CaO12 cuboctahedra, a faceface with one BaO12 cuboctahedra, faces with five equivalent CaO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.66–2.81 Å. Tb4+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Tb–O bond lengths are 2.41 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with five TiO6 octahedra, a cornercorner with one CuO5 square pyramid, faces with four equivalent BaO12 cuboctahedra, and faces with four equivalent CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Ti–O bond distances ranging from 1.94–1.99 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with eight equivalent CaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is two shorter (1.93 Å) and four longer (1.96 Å) Ti–O bond length. Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one TiO6 octahedra, corners with four equivalent CuO5 square pyramids, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.98 Å) and one longer (2.26 Å) Cu–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Tb4+, and two equivalent Cu2+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ca2+ and two Ti4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ca2+ and two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Ba2+, one Ti4+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OBa4TiCu octahedra. The corner-sharing octahedral tilt angles are 8°. In the fifth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, two equivalent Ca2+, and two equivalent Ti4+ atoms.