Materials Data on MgZr4O9 by Materials Project

Abstract

MgZr4O9 is Baddeleyite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted edge-sharing MgO6 octahedra. There are two shorter (2.02 Å) and four longer (2.19 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.90 Å) and two longer (2.15 Å) Mg–O bond lengths. There are four inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.05–2.36 Å. In the second Zr4+ site, Zr4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.11–2.29 Å. In the third Zr4+ site, Zr4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.08–2.34 Å. In the fourth Zr4+ site, Zr4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Zr–O bond distances ranging from 2.08–2.34 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Zr4+ atoms to form distorted OMgZr3 tetrahedra that share corners with six OMgZr3 tetrahedra, corners with four equivalent OMgZr3 trigonal pyramids, and edges with four OZr4 tetrahedra. In the second O2- site, O2- is bonded to three Mg2+ and one Zr4+ atom to form a mixture of edge and corner-sharing OMg3Zr tetrahedra. In the third O2- site, O2- is bonded to one Mg2+ and three Zr4+ atoms to form distorted OMgZr3 trigonal pyramids that share corners with ten OMgZr3 tetrahedra, corners with three equivalent OMgZr3 trigonal pyramids, and edges with two OZr4 tetrahedra. In the fourth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Zr4+ atoms. In the fifth O2- site, O2- is bonded to four Zr4+ atoms to form a mixture of distorted edge and corner-sharing OZr4 tetrahedra. In the sixth O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 tetrahedra that share corners with four OMg3Zr tetrahedra, corners with three equivalent OMgZr3 trigonal pyramids, edges with four OMgZr3 tetrahedra, and an edgeedge with one OMgZr3 trigonal pyramid. In the seventh O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Zr4+ atoms. In the eighth O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 tetrahedra that share corners with four OMgZr3 tetrahedra, corners with two equivalent OMgZr3 trigonal pyramids, and edges with four OZr4 tetrahedra. In the ninth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Zr4+ atoms.