Materials Data on Mg(WO2)2 by Materials Project

Abstract

Mg(WO2)2 is Ilmenite-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with three MgO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 53–61°. There are three shorter (2.04 Å) and one longer (2.13 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six WO4 trigonal pyramids, edges with two MgO6 octahedra, and edges with four WO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.10–2.21 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four WO4 trigonal pyramids, an edgeedge with one MgO6 octahedra, and edges with five WO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.12–2.16 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share edges with two MgO6 octahedra and edges with four WO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.11–2.18 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three WO4 trigonal pyramids, edges with two MgO6 octahedra, and edges with four equivalent WO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.09–2.17 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one MgO6 octahedra, and edges with five WO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.24 Å. There are nine inequivalent W3+ sites. In the first W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four WO4 trigonal pyramids, edges with three MgO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.22 Å. In the second W3+ site, W3+ is bonded to four O2- atoms to form WO4 trigonal pyramids that share corners with six MgO6 octahedra and corners with six WO6 octahedra. The corner-sharing octahedra tilt angles range from 39–69°. There are a spread of W–O bond distances ranging from 2.01–2.55 Å. In the third W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent WO4 trigonal pyramids, edges with two MgO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.15–2.18 Å. In the fourth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three WO4 trigonal pyramids, edges with two equivalent WO6 octahedra, and edges with four MgO6 octahedra. There are a spread of W–O bond distances ranging from 2.15–2.25 Å. In the fifth W3+ site, W3+ is bonded in a trigonal planar geometry to three O2- atoms. All W–O bond lengths are 2.02 Å. In the sixth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, edges with three MgO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.14–2.23 Å. In the seventh W3+ site, W3+ is bonded to four O2- atoms to form WO4 trigonal pyramids that share corners with six MgO6 octahedra and corners with six WO6 octahedra. The corner-sharing octahedra tilt angles range from 39–69°. There are a spread of W–O bond distances ranging from 2.01–2.47 Å. In the eighth W3+ site, W3+ is bonded in a trigonal planar geometry to three O2- atoms. All W–O bond lengths are 2.02 Å. In the ninth W3+ site, W3+ is bonded to four O2- atoms to form WO4 trigonal pyramids that share corners with three MgO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 45–67°. There are a spread of W–O bond distances ranging from 2.00–2.38 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two W3+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two W3+ atoms. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two equivalent W3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two W3+ atoms. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Mg2+ and three W3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two W3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two W3+ atoms. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two equivalent W3+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four W3+ atoms. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three W3+ atoms. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two equivalent W3+ atoms.