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DOE OSTI2020

Materials Data on MgNi2O5 by Materials Project

MgNi2O5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.41 Å. There are two inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.82–1.98 Å. In the second Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.83–1.98 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Mg2+ and two Ni4+ atoms to form corner-sharing OMg2Ni2 tetrahedra. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three equivalent Ni4+ atoms. In the third O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three equivalent Ni4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.51 Å. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+, one Ni4+, and one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 is Spinel structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with twelve NiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–66°. There is one shorter (1.97 Å) and three longer (1.98 Å) Mg–O bond length. There are four inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.89–2.14 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.89–2.13 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.89–2.14 Å. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.89–2.13 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMgNi3 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMgNi3 trigonal pyramids. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 is Spinel structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with twelve NiO6 octahedra. The corner-sharing octahedra tilt angles range from 55–62°. All Mg–O bond lengths are 1.99 Å. There are four inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.94–2.08 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.96–2.04 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.94–2.04 Å. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.95–2.04 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)4 by Materials Project

Mg(NiO2)4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with six NiO6 octahedra, edges with three NiO6 octahedra, edges with two equivalent MgO5 square pyramids, and a faceface with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 10–55°. There are a spread of Mg–O bond distances ranging from 2.04–2.16 Å. There are four inequivalent Ni+3.50+ sites. In the first Ni+3.50+ site, Ni+3.50+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four NiO6 octahedra, edges with four NiO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ni–O bond distances ranging from 1.88–1.97 Å. In the second Ni+3.50+ site, Ni+3.50+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four NiO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with four NiO6 octahedra, and a faceface with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Ni–O bond distances ranging from 1.90–2.09 Å. In the third Ni+3.50+ site, Ni+3.50+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four NiO6 octahedra, corners with two equivalent MgO5 square pyramids, and edges with four NiO6 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Ni–O bond distances ranging from 1.85–1.93 Å. In the fourth Ni+3.50+ site, Ni+3.50+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four NiO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with four NiO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Ni–O bond distances ranging from 1.87–2.05 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ni+3.50+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Ni+3.50+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three Ni+3.50+ atoms. In the fourth O2- site, O2- is bonded to one Mg2+ and three Ni+3.50+ atoms to form distorted OMgNi3 trigonal pyramids that share corners with two equivalent OMgNi3 trigonal pyramids, edges with two equivalent OMg2Ni3 square pyramids, and edges with two equivalent OMg2Ni3 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Ni+3.50+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Mg2+ and three Ni+3.50+ atoms to form distorted OMg2Ni3 trigonal bipyramids that share corners with two equivalent OMg2Ni3 square pyramids, an edgeedge with one OMg2Ni3 square pyramid, edges with two equivalent OMg2Ni3 trigonal bipyramids, and edges with two equivalent OMgNi3 trigonal pyramids. In the seventh O2- site, O2- is bonded to two equivalent Mg2+ and three Ni+3.50+ atoms to form OMg2Ni3 square pyramids that share corners with two equivalent OMg2Ni3 trigonal bipyramids, edges with two equivalent OMg2Ni3 square pyramids, an edgeedge with one OMg2Ni3 trigonal bipyramid, and edges with two equivalent OMgNi3 trigonal pyramids. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to three Ni+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.19–2.41 Å. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–63°. There is four shorter (1.92 Å) and two longer (2.00 Å) Ni–O bond length. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–63°. There are a spread of Ni–O bond distances ranging from 1.91–2.05 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 square pyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four NiO6 octahedra, corners with four NiO5 square pyramids, an edgeedge with one NiO5 square pyramid, edges with two equivalent MgO5 square pyramids, and a faceface with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 39–59°. There are a spread of Mg–O bond distances ranging from 1.99–2.11 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 square pyramids that share corners with four NiO6 octahedra, corners with four NiO5 square pyramids, an edgeedge with one NiO5 square pyramid, edges with two equivalent MgO5 square pyramids, and a faceface with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 39–59°. There are a spread of Mg–O bond distances ranging from 1.99–2.11 Å. There are four inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to five O2- atoms to form NiO5 square pyramids that share corners with four NiO6 octahedra, corners with four MgO5 square pyramids, an edgeedge with one MgO5 square pyramid, and edges with two equivalent NiO5 square pyramids. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ni–O bond distances ranging from 1.92–2.00 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four MgO5 square pyramids, corners with four NiO5 square pyramids, edges with four NiO6 octahedra, and a faceface with one MgO5 square pyramid. There are a spread of Ni–O bond distances ranging from 1.88–2.05 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four MgO5 square pyramids, corners with four NiO5 square pyramids, edges with four NiO6 octahedra, and a faceface with one MgO5 square pyramid. There are a spread of Ni–O bond distances ranging from 1.89–2.04 Å. In the fourth Ni3+ site, Ni3+ is bonded to five O2- atoms to form NiO5 square pyramids that share corners with four NiO6 octahedra, corners with four MgO5 square pyramids, an edgeedge with one MgO5 square pyramid, and edges with two equivalent NiO5 square pyramids. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ni–O bond distances ranging from 1.92–2.00 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form distorted OMgNi3 trigonal pyramids that share a cornercorner with one OMg2Ni3 trigonal bipyramid, corners with two equivalent OMgNi3 trigonal pyramids, and edges with two equivalent OMg2Ni3 trigonal bipyramids. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Ni3+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three Ni3+ atoms. In the fourth O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form distorted OMgNi3 trigonal pyramids that share a cornercorner with one OMg2Ni3 trigonal bipyramid, corners with two equivalent OMgNi3 trigonal pyramids, and edges with two equivalent OMg2Ni3 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a square co-planar geometry to two equivalent Mg2+ and two equivalent Ni3+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Mg2+ and three Ni3+ atoms to form distorted OMg2Ni3 trigonal bipyramids that share a cornercorner with one OMgNi3 trigonal pyramid, edges with four OMg2Ni3 trigonal bipyramids, and edges with two equivalent OMgNi3 trigonal pyramids. In the seventh O2- site, O2- is bonded in a square co-planar geometry to two equivalent Mg2+ and two equivalent Ni3+ atoms. In the eighth O2- site, O2- is bonded to two equivalent Mg2+ and three Ni3+ atoms to form distorted OMg2Ni3 trigonal bipyramids that share a cornercorner with one OMgNi3 trigonal pyramid, edges with four OMg2Ni3 trigonal bipyramids, and edges with two equivalent OMgNi3 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNiO2 by Materials Project

MgNiO2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with four equivalent MgO4 tetrahedra, corners with two equivalent NiO5 trigonal bipyramids, edges with two equivalent MgO5 trigonal bipyramids, and a faceface with one NiO5 trigonal bipyramid. There are three shorter (2.04 Å) and two longer (2.11 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with two equivalent MgO4 tetrahedra, corners with four equivalent MgO5 trigonal bipyramids, corners with four equivalent NiO5 trigonal bipyramids, and an edgeedge with one NiO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 1.95–1.99 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is two shorter (1.89 Å) and two longer (2.03 Å) Ni–O bond length. In the second Ni2+ site, Ni2+ is bonded to five O2- atoms to form distorted NiO5 trigonal bipyramids that share corners with four equivalent MgO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, an edgeedge with one MgO4 tetrahedra, edges with two equivalent NiO5 trigonal bipyramids, and a faceface with one MgO5 trigonal bipyramid. There are a spread of Ni–O bond distances ranging from 2.02–2.18 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Ni2+ atoms to form distorted OMgNi3 tetrahedra that share corners with two equivalent OMgNi3 tetrahedra, corners with four equivalent OMg3Ni2 trigonal bipyramids, and an edgeedge with one OMg3Ni2 trigonal bipyramid. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Mg2+ and two equivalent Ni2+ atoms. In the third O2- site, O2- is bonded to three Mg2+ and two equivalent Ni2+ atoms to form distorted OMg3Ni2 trigonal bipyramids that share corners with four equivalent OMgNi3 tetrahedra, an edgeedge with one OMgNi3 tetrahedra, and edges with two equivalent OMg3Ni2 trigonal bipyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two equivalent Ni2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 crystallizes in the monoclinic P2_1/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 MgO6 pentagonal pyramids that share corners with six equivalent NiO6 octahedra, edges with six NiO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 2–17°. There are four shorter (2.13 Å) and two longer (2.14 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 pentagonal pyramids that share corners with twelve NiO6 octahedra, edges with two equivalent MgO6 pentagonal pyramids, and faces with two equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–52°. There are a spread of Mg–O bond distances ranging from 2.08–2.17 Å. There are three inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with five MgO6 pentagonal pyramids, edges with six NiO6 octahedra, an edgeedge with one MgO6 pentagonal pyramid, and a faceface with one MgO6 pentagonal pyramid. There are a spread of Ni–O bond distances ranging from 1.87–2.08 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six NiO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Ni–O bond distances ranging from 1.89–2.04 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent MgO6 pentagonal pyramids, edges with six NiO6 octahedra, and edges with two equivalent MgO6 pentagonal pyramids. There are a spread of Ni–O bond distances ranging from 1.89–2.04 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the second O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form OMgNi3 trigonal pyramids that share corners with four OMg2Ni3 trigonal bipyramids, corners with three equivalent OMgNi3 trigonal pyramids, and edges with four OMg2Ni3 trigonal bipyramids. In the third O2- site, O2- is bonded to two Mg2+ and three Ni3+ atoms to form OMg2Ni3 trigonal bipyramids that share corners with five OMg2Ni3 trigonal bipyramids, corners with two equivalent OMgNi3 trigonal pyramids, edges with four OMg2Ni3 trigonal bipyramids, and edges with two equivalent OMgNi3 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Mg2+ and three Ni3+ atoms to form OMg2Ni3 trigonal bipyramids that share corners with five OMg2Ni3 trigonal bipyramids, corners with two equivalent OMgNi3 trigonal pyramids, edges with four OMg2Ni3 trigonal bipyramids, and edges with two equivalent OMgNi3 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg2Ni3O8 by Materials Project

Mg2Ni3O8 is Pyrite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.04–2.26 Å. There are two inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to six O2- atoms to form edge-sharing NiO6 octahedra. There is four shorter (1.88 Å) and two longer (1.89 Å) Ni–O bond length. In the second Ni4+ site, Ni4+ is bonded to six O2- atoms to form edge-sharing NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.85–1.91 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two equivalent Ni4+ atoms. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the third O2- site, O2- is bonded to two equivalent Mg2+ and two Ni4+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ni2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNi4O9 by Materials Project

MgNi4O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.07–2.51 Å. In the second Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.46 Å. There are eight inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.94–2.07 Å. In the second Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.03 Å. In the third Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 square pyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.03 Å. In the fourth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of distorted edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.93–2.05 Å. In the fifth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.85–2.08 Å. In the sixth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.90–2.08 Å. In the seventh Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.88–2.09 Å. In the eighth Ni4+ site, Ni4+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.90–2.08 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni4+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.33 Å. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.36 Å. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.36 Å. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. The O–O bond length is 1.32 Å. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ni4+, and one O2- atom. In the eleventh O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the fourteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the fifteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the sixteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted see-saw-like geometry to one Mg2+ and three Ni4+ atoms. In the eighteenth O2- site, O2- is bonded in a see-saw-like geometry to one Mg2+ and three Ni4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg3Ni2O7 by Materials Project

Mg3Ni2O7 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.28 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with eight equivalent MgO6 octahedra, edges with two equivalent NiO6 octahedra, and a faceface with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 43–75°. There are a spread of Mg–O bond distances ranging from 2.00–2.32 Å. Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with five equivalent NiO6 octahedra, edges with two equivalent MgO6 octahedra, and a faceface with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–62°. There are a spread of Ni–O bond distances ranging from 1.87–1.94 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Mg2+ and one Ni4+ atom to form distorted OMg3Ni tetrahedra that share corners with six equivalent OMg3Ni tetrahedra and a cornercorner with one OMg2Ni2 trigonal pyramid. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+ and two equivalent Ni4+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two equivalent Ni4+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Ni4+ atoms to form distorted OMg2Ni2 trigonal pyramids that share corners with two equivalent OMg3Ni tetrahedra and corners with two equivalent OMg2Ni2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg2Ni2O5 by Materials Project

Mg2Ni2O5 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Mg2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Mg–O bond distances ranging from 2.09–2.72 Å. Ni3+ is bonded to five O2- atoms to form corner-sharing NiO5 square pyramids. There are a spread of Ni–O bond distances ranging from 1.90–1.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent Ni3+ atoms to form distorted OMg4Ni2 octahedra that share corners with eight equivalent OMg2Ni2 tetrahedra, edges with two equivalent OMg4Ni2 octahedra, and edges with two equivalent OMg2Ni2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Ni3+ atoms to form OMg2Ni2 tetrahedra that share corners with four equivalent OMg4Ni2 octahedra, corners with four equivalent OMg2Ni2 tetrahedra, and an edgeedge with one OMg4Ni2 octahedra. The corner-sharing octahedra tilt angles range from 19–61°. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Mg2+ and two equivalent Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNiO2 by Materials Project

MgNiO2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with six NiO5 trigonal bipyramids, an edgeedge with one NiO5 trigonal bipyramid, edges with two equivalent MgO5 trigonal bipyramids, and a faceface with one NiO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.02–2.14 Å. In the second Mg2+ site, Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share corners with six NiO5 trigonal bipyramids, an edgeedge with one NiO5 trigonal bipyramid, edges with two equivalent MgO5 trigonal bipyramids, and a faceface with one NiO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.02–2.14 Å. In the third Mg2+ site, Mg2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.93–2.00 Å. In the fourth Mg2+ site, Mg2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Mg–O bond distances ranging from 1.93–2.00 Å. There are four inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to five O2- atoms to form distorted NiO5 trigonal bipyramids that share corners with four MgO5 trigonal bipyramids, corners with four NiO5 trigonal bipyramids, an edgeedge with one MgO5 trigonal bipyramid, and edges with two equivalent NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.22 Å. In the second Ni2+ site, Ni2+ is bonded to five O2- atoms to form distorted NiO5 trigonal bipyramids that share corners with two equivalent MgO5 trigonal bipyramids, corners with four NiO5 trigonal bipyramids, edges with two equivalent NiO5 trigonal bipyramids, and a faceface with one MgO5 trigonal bipyramid. There are a spread of Ni–O bond distances ranging from 1.98–2.15 Å. In the third Ni2+ site, Ni2+ is bonded to five O2- atoms to form distorted NiO5 trigonal bipyramids that share corners with two equivalent MgO5 trigonal bipyramids, corners with four NiO5 trigonal bipyramids, edges with two equivalent NiO5 trigonal bipyramids, and a faceface with one MgO5 trigonal bipyramid. There are a spread of Ni–O bond distances ranging from 1.98–2.17 Å. In the fourth Ni2+ site, Ni2+ is bonded to five O2- atoms to form distorted NiO5 trigonal bipyramids that share corners with four MgO5 trigonal bipyramids, corners with four NiO5 trigonal bipyramids, an edgeedge with one MgO5 trigonal bipyramid, and edges with two equivalent NiO5 trigonal bipyramids. There are a spread of Ni–O bond distances ranging from 1.95–2.23 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three Ni2+ atoms to form distorted OMgNi3 tetrahedra that share corners with two equivalent OMgNi3 tetrahedra, corners with eight OMg2Ni3 trigonal bipyramids, and an edgeedge with one OMg3Ni2 trigonal bipyramid. In the second O2- site, O2- is bonded to two equivalent Mg2+ and three Ni2+ atoms to form distorted OMg2Ni3 trigonal bipyramids that share corners with four OMgNi3 tetrahedra and edges with four OMg2Ni3 trigonal bipyramids. In the third O2- site, O2- is bonded to two equivalent Mg2+ and three Ni2+ atoms to form distorted OMg2Ni3 trigonal bipyramids that share corners with four OMgNi3 tetrahedra and edges with four OMg2Ni3 trigonal bipyramids. In the fourth O2- site, O2- is bonded to one Mg2+ and three Ni2+ atoms to form distorted OMgNi3 tetrahedra that share corners with two equivalent OMgNi3 tetrahedra, corners with eight OMg2Ni3 trigonal bipyramids, and an edgeedge with one OMg3Ni2 trigonal bipyramid. In the fifth O2- site, O2- is bonded to three Mg2+ and two equivalent Ni2+ atoms to form distorted OMg3Ni2 trigonal bipyramids that share corners with four OMgNi3 tetrahedra, an edgeedge with one OMgNi3 tetrahedra, and edges with four OMg2Ni3 trigonal bipyramids. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two equivalent Ni2+ atoms. In the seventh O2- site, O2- is bonded to three Mg2+ and two equivalent Ni2+ atoms to form distorted OMg3Ni2 trigonal bipyramids that share corners with four OMgNi3 tetrahedra, an edgeedge with one OMgNi3 tetrahedra, and edges with four OMg2Ni3 trigonal bipyramids. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two equivalent Ni2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 is Spinel-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are eight 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 NiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–63°. There are a spread of Mg–O bond distances ranging from 1.96–2.00 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three MgO4 tetrahedra, corners with three NiO4 tetrahedra, and edges with six NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.06 Å. In the third Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with three MgO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 56–62°. There are a spread of Mg–O bond distances ranging from 1.96–2.00 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four NiO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.06 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six NiO4 tetrahedra, edges with two MgO6 octahedra, and edges with four equivalent NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.07 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six NiO4 tetrahedra, edges with two MgO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.08 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five NiO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.07 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six NiO4 tetrahedra, edges with two MgO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.07 Å. There are twelve inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three MgO4 tetrahedra, corners with three NiO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.90–2.06 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent NiO4 tetrahedra, edges with two MgO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.91–2.06 Å. In the third Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six MgO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There is two shorter (1.88 Å) and two longer (1.90 Å) Ni–O bond length. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent MgO4 tetrahedra, corners with four NiO4 tetrahedra, edges with three MgO6 octahedra, and edges with three NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.87–2.02 Å. In the fifth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with three MgO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Ni–O bond distances ranging from 1.89–1.94 Å. In the sixth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six MgO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Ni–O bond distances ranging from 1.83–1.88 Å. In the seventh Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six NiO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four MgO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.87–2.02 Å. In the eighth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six MgO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–62°. There is three shorter (1.91 Å) and one longer (1.93 Å) Ni–O bond length. In the ninth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one MgO4 tetrahedra, corners with five NiO4 tetrahedra, edges with three MgO6 octahedra, and edges with three NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.91–2.10 Å. In the tenth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six MgO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Ni–O bond distances ranging from 1.90–2.02 Å. In the eleventh Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent NiO4 tetrahedra, edges with two MgO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.87–1.91 Å. In the twelfth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with three MgO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–62°. There is two shorter (1.96 Å) and two longer (1.98 Å) Ni–O bond length. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Mg2+ and two Ni3+ atoms to form distorted OMg2Ni2 trigonal pyramids that share a cornercorner with one OMg2Ni2 tetrahedra, corners with five OMgNi3 trigonal pyramids, and an edgeedge with one OMg2Ni2 trigonal pyramid. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mg2+ and two equivalent Ni3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni3+ atoms. In the fifth O2- site, O2- is bonded to two Mg2+ and two Ni3+ atoms to form a mixture of distorted corner and edge-sharing OMg2Ni2 trigonal pyramids. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the eighth O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form distorted corner-sharing OMgNi3 trigonal pyramids. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Ni3+ atoms. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Ni3+ atoms. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Mg2+ and two Ni3+ atoms. In the eighteenth O2- site, O2- is bonded to two Mg2+ and two Ni3+ atoms to form a mixture of distorted corner and edge-sharing OMg2Ni2 trigonal pyramids. In the nineteenth O2- site, O2- is bonded to two Mg2+ and two equivalent Ni3+ atoms to form distorted corner-sharing OMg2Ni2 tetrahedra. In the twentieth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the twenty-first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni3+ atoms. In the twenty-third O2- site, O2- is bonded to one Mg2+ and three Ni3+ atoms to form distorted OMgNi3 trigonal pyramids that share corners with two equivalent OMg2Ni2 tetrahedra, corners with four OMgNi3 trigonal pyramids, and an edgeedge with one OMgNi3 trigonal pyramid. In the twenty-fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(NiO2)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNiO2 by Materials Project

MgNiO2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form MgO6 octahedra that share corners with six equivalent NiO6 octahedra, edges with six equivalent MgO6 octahedra, and edges with six equivalent NiO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.11 Å. Ni2+ is bonded to six equivalent O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with six equivalent MgO6 octahedra, and edges with six equivalent NiO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ni–O bond lengths are 2.12 Å. O2- is bonded to three equivalent Mg2+ and three equivalent Ni2+ atoms to form a mixture of corner and edge-sharing OMg3Ni3 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNi9O13 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg3NiO4 by Materials Project

Mg3NiO4 is Caswellsilverite-like structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with four equivalent NiO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.12 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent NiO6 octahedra and edges with twelve equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ni–O bond lengths are 2.12 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent Ni2+ atoms to form OMg4Ni2 octahedra that share corners with six equivalent OMg4Ni2 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. All O–Mg bond lengths are 2.12 Å. In the second O2- site, O2- is bonded to six equivalent Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg4Ni2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent Ni2+ atoms to form a mixture of edge and corner-sharing OMg4Ni2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded to four equivalent Mg2+ and two equivalent Ni2+ atoms to form a mixture of edge and corner-sharing OMg4Ni2 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗