DOI: 10.17188/1207035
title: Materials Data on Mg(GaO2)2 by Materials Project

description: MgGa2O4 is Spinel-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 GaO6 octahedra. The corner-sharing octahedra tilt angles range from 57–60°. There is two shorter (1.97 Å) and two longer (2.00 Å) Mg–O bond length. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four GaO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five GaO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.09 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six GaO4 tetrahedra, edges with two MgO6 octahedra, and edges with four equivalent GaO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.08 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six GaO4 tetrahedra, edges with two MgO6 octahedra, and edges with four GaO6 octahedra. There are four shorter (2.07 Å) and two longer (2.09 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five GaO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five GaO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.09 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six GaO4 tetrahedra, edges with two MgO6 octahedra, and edges with four GaO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.10 Å. There are nine inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six MgO6 octahedra and corners with six GaO6 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. There are a spread of Ga–O bond distances ranging from 1.88–1.93 Å. In the second Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four GaO4 tetrahedra, edges with three MgO6 octahedra, and edges with three GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.07 Å. In the third Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent GaO4 tetrahedra, edges with two MgO6 octahedra, and edges with four GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.08 Å. In the fourth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six GaO4 tetrahedra, edges with two equivalent GaO6 octahedra, and edges with four MgO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.99–2.05 Å. In the fifth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six MgO6 octahedra and corners with six GaO6 octahedra. The corner-sharing octahedra tilt angles range from 55–57°. There is two shorter (1.87 Å) and two longer (1.91 Å) Ga–O bond length. In the sixth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five GaO4 tetrahedra, edges with three MgO6 octahedra, and edges with three GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.09 Å. In the seventh Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six MgO6 octahedra and corners with six GaO6 octahedra. The corner-sharing octahedra tilt angles range from 56–57°. There is two shorter (1.88 Å) and two longer (1.93 Å) Ga–O bond length. In the eighth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with six MgO6 octahedra and corners with six GaO6 octahedra. The corner-sharing octahedra tilt angles range from 56–58°. There are a spread of Ga–O bond distances ranging from 1.88–1.95 Å. In the ninth Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three MgO6 octahedra and corners with nine GaO6 octahedra. The corner-sharing octahedra tilt angles range from 56–59°. There are a spread of Ga–O bond distances ranging from 1.89–1.96 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 Ga3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mg2+ and two Ga3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Ga3+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Ga3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mg2+ and two Ga3+ atoms. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two equivalent Ga3+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ga3+ atoms. In the sixteenth O2- site, O2- is bonded to four Ga3+ atoms to form a mixture of distorted corner and edge-sharing OGa4 trigonal pyramids. In the seventeenth O2- site, O2- is bonded to one Mg2+ and three Ga3+ atoms to form a mixture of distorted corner and edge-sharing OMgGa3 trigonal pyramids. In the eighteenth O2- site, O2- is bonded to one Mg2+ and three Ga3+ atoms to form distorted edge-sharing OMgGa3 trigonal pyramids.