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DOE OSTI2020

Materials Data on Li(FeO2)2 by Materials Project

Li(FeO2)2 is Spinel-like structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li sites. In the first Li site, Li is bonded to four O atoms to form LiO4 tetrahedra that share corners with twelve FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–65°. There are a spread of Li–O bond distances ranging from 1.95–1.97 Å. In the second Li site, Li is bonded to four O atoms to form distorted LiO4 tetrahedra that share corners with six FeO6 octahedra and edges with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 60–65°. There are a spread of Li–O bond distances ranging from 1.77–1.96 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four LiO4 tetrahedra, edges with five FeO6 octahedra, and an edgeedge with one LiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Fe–O bond distances ranging from 1.91–1.98 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra, corners with six LiO4 tetrahedra, and edges with three FeO6 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Fe–O bond distances ranging from 1.99–2.05 Å. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four LiO4 tetrahedra, edges with five FeO6 octahedra, and an edgeedge with one LiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Fe–O bond distances ranging from 1.94–2.06 Å. In the fourth Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four LiO4 tetrahedra, edges with five FeO6 octahedra, and an edgeedge with one LiO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Fe–O bond distances ranging from 1.96–2.06 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li and three Fe atoms. In the second O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li and three Fe atoms. In the fourth O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the fifth O site, O is bonded to one Li and three Fe atoms to form distorted corner-sharing OLiFe3 tetrahedra. In the sixth O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms. In the seventh O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li and three Fe atoms. In the eighth O site, O is bonded to one Li and three Fe atoms to form distorted corner-sharing OLiFe3 tetrahedra.

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Materials Data on LiCr(FeO2)4 by Materials Project

LiCr(FeO2)4 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent CrO6 octahedra, and edges with four equivalent FeO6 octahedra. All Li–O bond lengths are 2.11 Å. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent LiO6 octahedra, and edges with four equivalent FeO6 octahedra. There are four shorter (2.03 Å) and two longer (2.05 Å) Cr–O bond lengths. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent LiO6 octahedra, corners with three equivalent CrO6 octahedra, and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 56–57°. There is three shorter (1.91 Å) and one longer (1.98 Å) Fe–O bond length. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent CrO6 octahedra, and edges with two equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.03–2.08 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Cr3+ and three Fe3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Fe3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr3+, and two Fe3+ atoms.

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Materials Data on Li2(FeO2)3 by Materials Project

Li2(FeO2)3 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Li is bonded in a distorted rectangular see-saw-like geometry to four equivalent O atoms. There are two shorter (2.03 Å) and two longer (2.10 Å) Li–O bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form edge-sharing FeO6 octahedra. There are two shorter (2.03 Å) and four longer (2.08 Å) Fe–O bond lengths. In the second Fe site, Fe is bonded to six O atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.12 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to three Fe atoms. In the second O site, O is bonded to two equivalent Li and three Fe atoms to form a mixture of distorted edge and corner-sharing OLi2Fe3 trigonal bipyramids.

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Materials Data on Li(FeO2)2 by Materials Project

Li(FeO2)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Li is bonded to six O atoms to form LiO6 octahedra that share corners with six equivalent FeO6 octahedra, edges with two equivalent LiO6 octahedra, and edges with six FeO6 octahedra. The corner-sharing octahedra tilt angles range from 9–12°. There are a spread of Li–O bond distances ranging from 2.13–2.31 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share edges with four equivalent LiO6 octahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.89–2.11 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent LiO6 octahedra, edges with two equivalent LiO6 octahedra, and edges with six FeO6 octahedra. The corner-sharing octahedra tilt angles range from 9–12°. There are a spread of Fe–O bond distances ranging from 2.04–2.08 Å. There are two inequivalent O sites. In the first O site, O is bonded to two equivalent Li and three Fe atoms to form a mixture of corner and edge-sharing OLi2Fe3 square pyramids. In the second O site, O is bonded in a rectangular see-saw-like geometry to one Li and three Fe atoms.

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Materials Data on MgZn(FeO2)4 by Materials Project

MgZn(FeO2)4 is Spinel-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent ZnO4 tetrahedra, and edges with six equivalent FeO6 octahedra. There are three shorter (2.06 Å) and three longer (2.12 Å) Mg–O bond lengths. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent ZnO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.09 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent MgO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. There is three shorter (1.90 Å) and one longer (2.02 Å) Fe–O bond length. Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three equivalent MgO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There are three shorter (1.98 Å) and one longer (2.02 Å) Zn–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Fe3+ and one Zn2+ atom. In the second O2- site, O2- is bonded to one Mg2+, two equivalent Fe3+, and one Zn2+ atom to form a mixture of distorted edge and corner-sharing OMgZnFe2 trigonal pyramids. In the third O2- site, O2- is bonded to four Fe3+ atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Fe3+ atoms.

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Materials Data on MnZn(FeO2)4 by Materials Project

MnZn(FeO2)4 is Spinel-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Mn2+ is bonded to four equivalent O2- atoms to form MnO4 tetrahedra that share corners with twelve equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Mn–O bond lengths are 2.04 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent MnO4 tetrahedra, corners with three equivalent ZnO4 tetrahedra, and edges with six equivalent FeO6 octahedra. There are three shorter (2.04 Å) and three longer (2.06 Å) Fe–O bond lengths. Zn2+ is bonded to four equivalent O2- atoms to form ZnO4 tetrahedra that share corners with twelve equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–O bond lengths are 2.01 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mn2+ and three equivalent Fe3+ atoms to form a mixture of distorted edge and corner-sharing OMnFe3 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Fe3+ and one Zn2+ atom to form distorted OZnFe3 trigonal pyramids that share corners with twelve OMnFe3 trigonal pyramids and edges with three equivalent OZnFe3 trigonal pyramids.

36 MATERIALS SCIENCE↗
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Materials Data on Sr4Ca(FeO2)5 by Materials Project

Sr4Ca(FeO2)5 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.66 Å) and four longer (2.68 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Sr–O bond lengths are 2.66 Å. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ca–O bond lengths are 2.62 Å. There are three inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.04 Å) Fe–O bond lengths. In the second Fe2+ site, Fe2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. All Fe–O bond lengths are 2.03 Å. In the third Fe2+ site, Fe2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.03 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Sr2+ and two Fe2+ atoms to form a mixture of edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the second O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Fe2+ atoms to form a mixture of edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the third O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Ca2+, and two Fe2+ atoms to form a mixture of distorted edge, corner, and face-sharing OSr2Ca2Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°.

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Materials Data on Mn(FeO2)2 by Materials Project

MnFe2O4 is Spinel structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Mn2+ is bonded to four equivalent O2- atoms to form MnO4 tetrahedra that share corners with twelve equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Mn–O bond lengths are 2.09 Å. Fe3+ is bonded to six equivalent O2- atoms to form FeO6 octahedra that share corners with six equivalent MnO4 tetrahedra and edges with six equivalent FeO6 octahedra. All Fe–O bond lengths are 2.06 Å. O2- is bonded to one Mn2+ and three equivalent Fe3+ atoms to form a mixture of distorted edge and corner-sharing OMnFe3 trigonal pyramids.

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Materials Data on BaCa(FeO2)4 by Materials Project

BaCaFe4O8 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share edges with six equivalent BaO12 cuboctahedra, edges with twelve equivalent FeO4 tetrahedra, and faces with two equivalent CaO6 octahedra. There are six shorter (3.00 Å) and six longer (3.19 Å) Ba–O bond lengths. Ca2+ is bonded to six equivalent O2- atoms to form CaO6 octahedra that share corners with twelve equivalent FeO4 tetrahedra and faces with two equivalent BaO12 cuboctahedra. All Ca–O bond lengths are 2.38 Å. Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent CaO6 octahedra, corners with four equivalent FeO4 tetrahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 57°. There is one shorter (1.88 Å) and three longer (1.91 Å) Fe–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, one Ca2+, and two equivalent Fe3+ atoms. In the second O2- site, O2- is bonded in a linear geometry to three equivalent Ba2+ and two equivalent Fe3+ atoms.

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Materials Data on Ba(FeO2)2 by Materials Project

BaFe2O4 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.71–3.32 Å. In the second Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.73–3.03 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.89–1.92 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. There is one shorter (1.90 Å) and three longer (1.91 Å) Fe–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Ba2+ and two Fe3+ atoms. In the second O2- site, O2- is bonded to two Ba2+ and two equivalent Fe3+ atoms to form distorted corner-sharing OBa2Fe2 trigonal pyramids. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Ba2+ and two equivalent Fe3+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to three equivalent Ba2+ and two equivalent Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+ and two equivalent Fe3+ atoms.

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Materials Data on Y(FeO2)2 by Materials Project

YFe2O4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Y3+ is bonded to six equivalent O2- atoms to form YO6 octahedra that share corners with six equivalent FeO5 trigonal bipyramids and edges with six equivalent YO6 octahedra. All Y–O bond lengths are 2.29 Å. Fe+2.50+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent YO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. There are a spread of Fe–O bond distances ranging from 1.99–2.14 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Fe+2.50+ atoms to form OFe4 trigonal pyramids that share corners with four equivalent OY3Fe tetrahedra, corners with six equivalent OFe4 trigonal pyramids, and edges with three equivalent OFe4 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Y3+ and one Fe+2.50+ atom to form OY3Fe tetrahedra that share corners with nine equivalent OY3Fe tetrahedra, corners with four equivalent OFe4 trigonal pyramids, and edges with three equivalent OY3Fe tetrahedra.

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Materials Data on Ba(FeO2)2 by Materials Project

BaFe2O4 crystallizes in the hexagonal P6_322 space group. The structure is three-dimensional. Ba2+ is bonded in a distorted q6 geometry to nine O2- atoms. There are six shorter (2.93 Å) and three longer (3.18 Å) Ba–O bond lengths. Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. There is one shorter (1.87 Å) and three longer (1.90 Å) Fe–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to three equivalent Ba2+ and two equivalent Fe3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two equivalent Fe3+ atoms.

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Materials Data on Zn(FeO2)2 by Materials Project

ZnFe2O4 is Spinel structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Fe3+ is bonded to six equivalent O2- atoms to form FeO6 octahedra that share corners with six equivalent ZnO4 tetrahedra and edges with six equivalent FeO6 octahedra. All Fe–O bond lengths are 2.05 Å. Zn2+ is bonded to four equivalent O2- atoms to form ZnO4 tetrahedra that share corners with twelve equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Zn–O bond lengths are 2.00 Å. O2- is bonded to three equivalent Fe3+ and one Zn2+ atom to form a mixture of distorted edge and corner-sharing OZnFe3 trigonal pyramids.

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Materials Data on Yb(FeO2)2 by Materials Project

YbFe2O4 is Aluminum carbonitride-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Yb2+ is bonded to six O2- atoms to form YbO6 octahedra that share corners with six equivalent FeO5 trigonal bipyramids and edges with six equivalent YbO6 octahedra. All Yb–O bond lengths are 2.32 Å. Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent YbO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 60°. There are a spread of Fe–O bond distances ranging from 1.82–2.20 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Fe3+ atoms to form a mixture of distorted edge and corner-sharing OFe4 tetrahedra. In the second O2- site, O2- is bonded to three equivalent Yb2+ and one Fe3+ atom to form distorted OYb3Fe tetrahedra that share corners with thirteen OFe4 tetrahedra and edges with three equivalent OYb3Fe tetrahedra. In the third O2- site, O2- is bonded to three equivalent Yb2+ and one Fe3+ atom to form distorted OYb3Fe tetrahedra that share corners with thirteen OFe4 tetrahedra and edges with three equivalent OYb3Fe tetrahedra. The O–Fe bond length is 1.82 Å. In the fourth O2- site, O2- is bonded to three equivalent Yb2+ and one Fe3+ atom to form distorted OYb3Fe tetrahedra that share corners with thirteen OFe4 tetrahedra and edges with three equivalent OYb3Fe tetrahedra. All O–Yb bond lengths are 2.32 Å. The O–Fe bond length is 1.82 Å.

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Materials Data on Lu(FeO2)2 by Materials Project

LuFe2O4 is Aluminum carbonitride-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Lu3+ is bonded to six equivalent O2- atoms to form distorted LuO6 octahedra that share corners with six equivalent FeO5 trigonal bipyramids and edges with six equivalent LuO6 octahedra. There are four shorter (2.24 Å) and two longer (2.26 Å) Lu–O bond lengths. Fe+2.50+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent LuO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 63°. There are a spread of Fe–O bond distances ranging from 2.00–2.18 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Fe+2.50+ atoms to form OFe4 trigonal pyramids that share corners with four equivalent OLu3Fe tetrahedra, corners with six equivalent OFe4 trigonal pyramids, and edges with three equivalent OFe4 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Lu3+ and one Fe+2.50+ atom to form OLu3Fe tetrahedra that share corners with nine equivalent OLu3Fe tetrahedra, corners with four equivalent OFe4 trigonal pyramids, and edges with three equivalent OLu3Fe tetrahedra.

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Materials Data on Er(FeO2)2 by Materials Project

ErFe2O4 is Aluminum carbonitride-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Er3+ is bonded to six equivalent O2- atoms to form ErO6 octahedra that share corners with six equivalent FeO5 trigonal bipyramids and edges with six equivalent ErO6 octahedra. All Er–O bond lengths are 2.27 Å. Fe+2.50+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with three equivalent ErO6 octahedra, corners with six equivalent FeO5 trigonal bipyramids, and edges with three equivalent FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. There are a spread of Fe–O bond distances ranging from 1.99–2.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Fe+2.50+ atoms to form OFe4 trigonal pyramids that share corners with four equivalent OEr3Fe tetrahedra, corners with six equivalent OFe4 trigonal pyramids, and edges with three equivalent OFe4 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Er3+ and one Fe+2.50+ atom to form OEr3Fe tetrahedra that share corners with nine equivalent OEr3Fe tetrahedra, corners with four equivalent OFe4 trigonal pyramids, and edges with three equivalent OEr3Fe tetrahedra.

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Materials Data on Mg(FeO2)2 by Materials Project

MgFe2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four equivalent FeO6 octahedra. There are four shorter (2.09 Å) and two longer (2.10 Å) Mg–O bond lengths. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent MgO6 octahedra and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 56–57°. There is two shorter (1.91 Å) and two longer (1.97 Å) Fe–O bond length. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four equivalent MgO6 octahedra. There are two shorter (2.04 Å) and four longer (2.07 Å) Fe–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Fe3+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg2+ and two Fe3+ atoms.

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Materials Data on Ti(FeO2)2 by Materials Project

Fe2TiO4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent TiO6 octahedra, and edges with four equivalent FeO6 octahedra. There is two shorter (1.97 Å) and four longer (2.02 Å) Ti–O bond length. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent TiO6 octahedra and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–62°. There are two shorter (2.03 Å) and two longer (2.07 Å) Fe–O bond lengths. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four equivalent TiO6 octahedra. There are four shorter (2.13 Å) and two longer (2.21 Å) Fe–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ti4+ and two Fe2+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ti4+ and three Fe2+ atoms.

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