Materials Data on Ba2Zr7O16 by Materials Project
Ba2Zr7O16 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.70–2.76 Å. There are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six equivalent O2- atoms to form corner-sharing ZrO6 octahedra. All Zr–O bond lengths are 2.14 Å. In the second Zr4+ site, Zr4+ is bonded to seven O2- atoms to form distorted ZrO7 pentagonal bipyramids that share a cornercorner with one ZrO6 octahedra, corners with two equivalent ZrO7 pentagonal bipyramids, and edges with seven equivalent ZrO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 36°. There are a spread of Zr–O bond distances ranging from 2.08–2.35 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ba2+ and three equivalent Zr4+ atoms to form distorted OBaZr3 tetrahedra that share corners with ten OBaZr3 tetrahedra and edges with three equivalent OZr4 tetrahedra. In the second O2- site, O2- is bonded to one Ba2+ and three equivalent Zr4+ atoms to form distorted OBaZr3 tetrahedra that share corners with ten OBaZr3 tetrahedra and edges with three equivalent OZr4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two Zr4+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Zr4+ atoms to form a mixture of distorted edge and corner-sharing OZr4 tetrahedra.