Materials Data on YZr4O9 by Materials Project
YZr4O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Y3+ is bonded to seven O2- atoms to form distorted YO7 pentagonal bipyramids that share corners with two ZrO7 pentagonal bipyramids and edges with four ZrO7 pentagonal bipyramids. There are a spread of Y–O bond distances ranging from 2.27–2.45 Å. There are four inequivalent Zr+3.75+ sites. In the first Zr+3.75+ site, Zr+3.75+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.09–2.48 Å. In the second Zr+3.75+ site, Zr+3.75+ is bonded to seven O2- atoms to form distorted ZrO7 pentagonal bipyramids that share a cornercorner with one YO7 pentagonal bipyramid, a cornercorner with one ZrO7 pentagonal bipyramid, edges with two equivalent YO7 pentagonal bipyramids, and edges with two equivalent ZrO7 pentagonal bipyramids. There are a spread of Zr–O bond distances ranging from 2.10–2.39 Å. In the third Zr+3.75+ site, Zr+3.75+ is bonded to seven O2- atoms to form distorted ZrO7 pentagonal bipyramids that share a cornercorner with one YO7 pentagonal bipyramid, a cornercorner with one ZrO7 pentagonal bipyramid, edges with two equivalent YO7 pentagonal bipyramids, and edges with two equivalent ZrO7 pentagonal bipyramids. There are a spread of Zr–O bond distances ranging from 2.14–2.29 Å. In the fourth Zr+3.75+ site, Zr+3.75+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.07–2.41 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form distorted OYZr3 tetrahedra that share corners with ten OYZr3 tetrahedra, corners with three equivalent OZr4 trigonal pyramids, and edges with four OZr4 tetrahedra. In the second O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form OYZr3 tetrahedra that share corners with eleven OYZr3 tetrahedra, a cornercorner with one OZr4 trigonal pyramid, edges with four OYZr3 tetrahedra, and an edgeedge with one OZr4 trigonal pyramid. In the third O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form distorted OYZr3 tetrahedra that share corners with twelve OYZr3 tetrahedra, a cornercorner with one OZr4 trigonal pyramid, edges with three OYZr3 tetrahedra, and an edgeedge with one OZr4 trigonal pyramid. In the fourth O2- site, O2- is bonded to four Zr+3.75+ atoms to form distorted OZr4 tetrahedra that share corners with twelve OYZr3 tetrahedra, edges with three OYZr3 tetrahedra, and edges with two equivalent OZr4 trigonal pyramids. In the fifth O2- site, O2- is bonded to four Zr+3.75+ atoms to form distorted OZr4 trigonal pyramids that share corners with twelve OYZr3 tetrahedra and edges with five OZr4 tetrahedra. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Y3+ and two Zr+3.75+ atoms. In the seventh O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form distorted OYZr3 tetrahedra that share corners with nine OYZr3 tetrahedra, corners with three equivalent OZr4 trigonal pyramids, and edges with five OZr4 tetrahedra. In the eighth O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form OYZr3 tetrahedra that share corners with eleven OYZr3 tetrahedra, a cornercorner with one OZr4 trigonal pyramid, edges with four OYZr3 tetrahedra, and an edgeedge with one OZr4 trigonal pyramid. In the ninth O2- site, O2- is bonded to one Y3+ and three Zr+3.75+ atoms to form distorted OYZr3 tetrahedra that share corners with nine OYZr3 tetrahedra, corners with three equivalent OZr4 trigonal pyramids, and edges with five OZr4 tetrahedra.