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DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–3.05 Å. In the second Mg site, Mg is bonded in a 6-coordinate geometry to one Mg and six Si atoms. The Mg–Mg bond length is 3.15 Å. There are a spread of Mg–Si bond distances ranging from 2.69–3.13 Å. In the third Mg site, Mg is bonded in a 10-coordinate geometry to nine Mg and one Si atom. There are a spread of Mg–Mg bond distances ranging from 2.98–3.16 Å. The Mg–Si bond length is 3.22 Å. In the fourth Mg site, Mg is bonded in a 5-coordinate geometry to one Mg and six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.24 Å. In the fifth Mg site, Mg is bonded in a 2-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.06 Å. In the sixth Mg site, Mg is bonded in a 4-coordinate geometry to one Mg and five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–3.19 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–3.17 Å. In the eighth Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Mg and three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.06 Å. In the ninth Mg site, Mg is bonded in a distorted linear geometry to two Si atoms. There are one shorter (2.71 Å) and one longer (2.78 Å) Mg–Si bond lengths. In the tenth Mg site, Mg is bonded in a distorted linear geometry to two Si atoms. There are one shorter (2.69 Å) and one longer (2.79 Å) Mg–Si bond lengths. In the eleventh Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.81–3.00 Å. In the twelfth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.89–2.93 Å. In the thirteenth Mg site, Mg is bonded in a distorted linear geometry to two equivalent Mg and two Si atoms. There are one shorter (2.73 Å) and one longer (2.84 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted single-bond geometry to two equivalent Mg and one Si atom. The Mg–Si bond length is 2.72 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 1-coordinate geometry to five Mg and two Si atoms. There are one shorter (2.47 Å) and one longer (2.57 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.45 Å) and one longer (2.68 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two equivalent Si atoms. There are one shorter (2.52 Å) and one longer (2.88 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.45 Å) and one longer (2.57 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. In the sixth Si site, Si is bonded in a 2-coordinate geometry to five Mg and three Si atoms. In the seventh Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the eighth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.85 Å. In the second Mg site, Mg is bonded to four Si atoms to form distorted corner-sharing MgSi4 trigonal pyramids. There are a spread of Mg–Si bond distances ranging from 2.74–2.91 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.84 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–2.91 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.66–2.82 Å. In the sixth Mg site, Mg is bonded in a distorted water-like geometry to two Si atoms. There are one shorter (2.78 Å) and one longer (2.86 Å) Mg–Si bond lengths. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.18 Å. In the eighth Mg site, Mg is bonded in a distorted water-like geometry to two Si atoms. There are one shorter (2.75 Å) and one longer (2.83 Å) Mg–Si bond lengths. In the ninth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–2.89 Å. In the tenth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.73–2.77 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are one shorter (2.79 Å) and two longer (2.84 Å) Mg–Si bond lengths. In the twelfth Mg site, Mg is bonded in a distorted rectangular see-saw-like geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.84 Å. In the thirteenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.91 Å. In the fourteenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–2.93 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. There are one shorter (2.38 Å) and one longer (2.40 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.47 Å. In the third Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the fourth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. There are one shorter (2.36 Å) and one longer (2.44 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. In the sixth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.44 Å. In the seventh Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the eighth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–2.99 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.19 Å. In the third Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–2.97 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.03 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are one shorter (2.96 Å) and two longer (3.11 Å) Mg–Si bond lengths. In the sixth Mg site, Mg is bonded in a distorted L-shaped geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.79–3.22 Å. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.94 Å. In the eighth Mg site, Mg is bonded in a 1-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.70–3.24 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–2.95 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–2.83 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.82–3.13 Å. In the twelfth Mg site, Mg is bonded in a 3-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.14 Å. In the thirteenth Mg site, Mg is bonded in a 2-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.87–3.11 Å. In the fourteenth Mg site, Mg is bonded in a 2-coordinate geometry to two Si atoms. There are one shorter (2.70 Å) and one longer (2.98 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.40 Å) and one longer (2.52 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.45 Å) and one longer (2.57 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.39 Å) and one longer (2.49 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. In the sixth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.42 Å. In the seventh Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–3.02 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.02 Å. In the third Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–2.93 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.04 Å. In the fifth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.84 Å) and one longer (2.93 Å) Mg–Si bond lengths. In the sixth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.76 Å) and one longer (2.77 Å) Mg–Si bond lengths. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.94 Å. In the eighth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.91 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.73–2.93 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.84 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.87–2.95 Å. In the twelfth Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–3.09 Å. In the thirteenth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.89 Å. In the fourteenth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.81 Å) and one longer (2.96 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.40 Å) and one longer (2.44 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.40 Å) and one longer (2.42 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.39 Å) and one longer (2.42 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. In the sixth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.42 Å. In the seventh Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the eighth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.23 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.30 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–3.07 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.84–3.24 Å. In the fifth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.85 Å) and one longer (2.92 Å) Mg–Si bond lengths. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–2.99 Å. In the seventh Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–3.08 Å. In the eighth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.80 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–3.01 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.81 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.94 Å. In the twelfth Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–2.97 Å. In the thirteenth Mg site, Mg is bonded in a 1-coordinate geometry to two Si atoms. There are one shorter (2.87 Å) and one longer (3.12 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted water-like geometry to two Si atoms. There are one shorter (2.69 Å) and one longer (2.89 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.43 Å) and one longer (2.46 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. Both Si–Si bond lengths are 2.56 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.40 Å) and one longer (2.44 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. In the sixth Si site, Si is bonded in a 10-coordinate geometry to eight Mg and two Si atoms. The Si–Si bond length is 2.45 Å. In the seventh Si site, Si is bonded in a 7-coordinate geometry to six Mg and one Si atom. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li10Sc9Fe(SiO3)20 by Materials Project

Li10Sc9Fe(SiO3)20 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are six inequivalent Li sites. In the first Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are two shorter (2.10 Å) and two longer (2.12 Å) Li–O bond lengths. In the second Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Li–O bond distances ranging from 2.09–2.12 Å. In the third Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Li–O bond distances ranging from 2.10–2.13 Å. In the fourth Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Li–O bond distances ranging from 2.10–2.13 Å. In the fifth Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Li–O bond distances ranging from 2.09–2.13 Å. In the sixth Li site, Li is bonded in a rectangular see-saw-like geometry to four O atoms. There are two shorter (2.09 Å) and two longer (2.11 Å) Li–O bond lengths. There are five inequivalent Sc sites. In the first Sc site, Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent ScO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.02–2.27 Å. In the second Sc site, Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six SiO4 tetrahedra and edges with two ScO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.02–2.29 Å. In the third Sc site, Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six SiO4 tetrahedra and edges with two ScO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.01–2.27 Å. In the fourth Sc site, Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six SiO4 tetrahedra and edges with two ScO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.02–2.27 Å. In the fifth Sc site, Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one ScO6 octahedra, and an edgeedge with one FeO6 octahedra. There are a spread of Sc–O bond distances ranging from 2.01–2.27 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent ScO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.24 Å. There are ten inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two ScO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–59°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two ScO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two ScO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the ninth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. In the tenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three ScO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–60°. There is one shorter (1.62 Å) and three longer (1.65 Å) Si–O bond length. There are thirty inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the third O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the sixth O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the ninth O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the tenth O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the eleventh O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the twelfth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourteenth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the fifteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li, two Sc, and one Si atom. In the sixteenth O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the seventeenth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the eighteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the nineteenth O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the twentieth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the twenty-first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-third O site, O is bonded to one Li, two Sc, and one Si atom to form a mixture of distorted corner and edge-sharing OLiSc2Si trigonal pyramids. In the twenty-fourth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom. In the twenty-fifth O site, O is bonded in a distorted T-shaped geometry to one Li, one Fe, and one Si atom. In the twenty-sixth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Li, one Sc, one Fe, and one Si atom. In the twenty-seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-eighth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-ninth O site, O is bonded to one Li, one Sc, one Fe, and one Si atom to form a mixture of distorted corner and edge-sharing OLiScFeSi trigonal pyramids. In the thirtieth O site, O is bonded in a distorted T-shaped geometry to one Li, one Sc, and one Si atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 2-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.82–3.16 Å. In the second Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.94 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.67–3.01 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.08 Å. In the fifth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.88 Å) and one longer (3.07 Å) Mg–Si bond lengths. In the sixth Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.25 Å. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.83 Å. In the eighth Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.15 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.91 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.78 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–3.04 Å. In the twelfth Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.79–3.10 Å. In the thirteenth Mg site, Mg is bonded in a 1-coordinate geometry to two Si atoms. There are one shorter (2.93 Å) and one longer (3.21 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted linear geometry to two Si atoms. There are one shorter (2.73 Å) and one longer (2.83 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.41 Å) and one longer (2.44 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.46 Å) and one longer (2.54 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.41 Å) and one longer (2.45 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. In the sixth Si site, Si is bonded in a 10-coordinate geometry to eight Mg and two Si atoms. The Si–Si bond length is 2.40 Å. In the seventh Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn14Si23 by Materials Project

Mn14Si23 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are seven inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded in a 10-coordinate geometry to ten Si+1.22- atoms. There are a spread of Mn–Si bond distances ranging from 2.64–2.94 Å. In the second Mn2+ site, Mn2+ is bonded in a 11-coordinate geometry to eleven Si+1.22- atoms. There are a spread of Mn–Si bond distances ranging from 2.54–3.06 Å. In the third Mn2+ site, Mn2+ is bonded in a 1-coordinate geometry to one Mn2+ and ten Si+1.22- atoms. The Mn–Mn bond length is 2.52 Å. There are a spread of Mn–Si bond distances ranging from 2.34–2.96 Å. In the fourth Mn2+ site, Mn2+ is bonded in a 8-coordinate geometry to eight Si+1.22- atoms. There are a spread of Mn–Si bond distances ranging from 2.28–2.50 Å. In the fifth Mn2+ site, Mn2+ is bonded in a 10-coordinate geometry to ten Si+1.22- atoms. There are a spread of Mn–Si bond distances ranging from 2.44–2.96 Å. In the sixth Mn2+ site, Mn2+ is bonded in a 5-coordinate geometry to seven Si+1.22- atoms. There are a spread of Mn–Si bond distances ranging from 2.21–2.80 Å. In the seventh Mn2+ site, Mn2+ is bonded to one Mn2+ and six Si+1.22- atoms to form distorted corner-sharing MnMnSi6 hexagonal pyramids. The Mn–Mn bond length is 2.18 Å. There are a spread of Mn–Si bond distances ranging from 2.42–2.50 Å. There are nine inequivalent Si+1.22- sites. In the first Si+1.22- site, Si+1.22- is bonded in a 4-coordinate geometry to four Mn2+ and six Si+1.22- atoms. There are a spread of Si–Si bond distances ranging from 2.39–2.49 Å. In the second Si+1.22- site, Si+1.22- is bonded in a 10-coordinate geometry to five Mn2+ and five Si+1.22- atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.69 Å. In the third Si+1.22- site, Si+1.22- is bonded in a 11-coordinate geometry to six Mn2+ and five Si+1.22- atoms. There are two shorter (2.41 Å) and two longer (2.58 Å) Si–Si bond lengths. In the fourth Si+1.22- site, Si+1.22- is bonded in a distorted bent 150 degrees geometry to six Mn2+ and five Si+1.22- atoms. There are one shorter (2.56 Å) and two longer (2.68 Å) Si–Si bond lengths. In the fifth Si+1.22- site, Si+1.22- is bonded to six Mn2+ and six Si+1.22- atoms to form edge-sharing SiMn6Si6 cuboctahedra. All Si–Si bond lengths are 2.39 Å. In the sixth Si+1.22- site, Si+1.22- is bonded in a distorted single-bond geometry to five Mn2+ and four Si+1.22- atoms. Both Si–Si bond lengths are 2.70 Å. In the seventh Si+1.22- site, Si+1.22- is bonded in a 12-coordinate geometry to six Mn2+ and six Si+1.22- atoms. There are a spread of Si–Si bond distances ranging from 2.33–2.66 Å. In the eighth Si+1.22- site, Si+1.22- is bonded in a 2-coordinate geometry to six Mn2+ and four Si+1.22- atoms. Both Si–Si bond lengths are 2.39 Å. In the ninth Si+1.22- site, Si+1.22- is bonded in a 11-coordinate geometry to five Mn2+ and six Si+1.22- atoms. There are one shorter (2.27 Å) and one longer (2.72 Å) Si–Si bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si6O13 by Materials Project

(Si4O7)6(O2)5 crystallizes in the monoclinic Pm space group. The structure is three-dimensional and consists of four hydrogen peroxide molecules, two water molecules, and one Si4O7 framework. In the Si4O7 framework, there are twelve inequivalent Si sites. In the first Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the third Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the fourth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.73 Å. In the fifth Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the sixth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the seventh Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.63 Å) Si–O bond length. In the eighth Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the ninth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.63 Å. In the tenth Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the eleventh Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There is two shorter (1.64 Å) and one longer (1.65 Å) Si–O bond length. In the twelfth Si site, Si is bonded in a trigonal non-coplanar geometry to three O atoms. There is two shorter (1.64 Å) and one longer (1.65 Å) Si–O bond length. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a linear geometry to two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a linear geometry to two equivalent Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent Si and one O atom. The O–O bond length is 1.51 Å. In the ninth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twelfth O site, O is bonded in a linear geometry to two equivalent Si atoms. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventeenth O site, O is bonded in a single-bond geometry to one O atom. In the eighteenth O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms. In the nineteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twentieth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-first O site, O is bonded in a linear geometry to two equivalent Si atoms. In the twenty-second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr20AlSi19N33Cl2O19 by Materials Project

Pr20AlSi19N33O19Cl2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are fourteen inequivalent Pr sites. In the first Pr site, Pr is bonded to five N and three O atoms to form distorted PrN5O3 hexagonal bipyramids that share corners with two PrN3O4 pentagonal bipyramids, an edgeedge with one PrN5O3 hexagonal bipyramid, an edgeedge with one AlN2O2 tetrahedra, and edges with five SiN4 tetrahedra. There are a spread of Pr–N bond distances ranging from 2.53–2.83 Å. There are a spread of Pr–O bond distances ranging from 2.58–2.62 Å. In the second Pr site, Pr is bonded to three N and four O atoms to form distorted PrN3O4 pentagonal bipyramids that share corners with two equivalent PrN5O3 hexagonal bipyramids, a cornercorner with one SiN3O tetrahedra, an edgeedge with one AlN2O2 tetrahedra, and edges with three SiN3O tetrahedra. There are one shorter (2.45 Å) and two longer (2.59 Å) Pr–N bond lengths. There are a spread of Pr–O bond distances ranging from 2.45–2.86 Å. In the third Pr site, Pr is bonded in a 9-coordinate geometry to six N, two equivalent O, and one Cl atom. There are a spread of Pr–N bond distances ranging from 2.49–3.10 Å. Both Pr–O bond lengths are 2.71 Å. The Pr–Cl bond length is 3.23 Å. In the fourth Pr site, Pr is bonded in a 7-coordinate geometry to four N and three O atoms. There are a spread of Pr–N bond distances ranging from 2.36–2.68 Å. There are a spread of Pr–O bond distances ranging from 2.45–2.75 Å. In the fifth Pr site, Pr is bonded in a 8-coordinate geometry to three N, four O, and one Cl atom. There are a spread of Pr–N bond distances ranging from 2.55–2.66 Å. There are a spread of Pr–O bond distances ranging from 2.36–2.87 Å. The Pr–Cl bond length is 3.16 Å. In the sixth Pr site, Pr is bonded in a 6-coordinate geometry to six N and two equivalent O atoms. There are a spread of Pr–N bond distances ranging from 2.40–3.06 Å. Both Pr–O bond lengths are 2.71 Å. In the seventh Pr site, Pr is bonded to three N and four O atoms to form distorted PrN3O4 pentagonal bipyramids that share corners with two equivalent PrN5O3 hexagonal bipyramids, a cornercorner with one SiN4 tetrahedra, an edgeedge with one AlN2O2 tetrahedra, and edges with three SiN2O2 tetrahedra. There are one shorter (2.46 Å) and two longer (2.63 Å) Pr–N bond lengths. There are a spread of Pr–O bond distances ranging from 2.39–2.71 Å. In the eighth Pr site, Pr is bonded in a 8-coordinate geometry to four N and four O atoms. There are a spread of Pr–N bond distances ranging from 2.55–2.83 Å. There are a spread of Pr–O bond distances ranging from 2.47–2.59 Å. In the ninth Pr site, Pr is bonded in a 7-coordinate geometry to four N and three O atoms. There are a spread of Pr–N bond distances ranging from 2.47–2.63 Å. There are two shorter (2.46 Å) and one longer (2.68 Å) Pr–O bond lengths. In the tenth Pr site, Pr is bonded in a 9-coordinate geometry to six N, two equivalent O, and one Cl atom. There are a spread of Pr–N bond distances ranging from 2.51–3.16 Å. Both Pr–O bond lengths are 2.69 Å. The Pr–Cl bond length is 3.17 Å. In the eleventh Pr site, Pr is bonded in a 7-coordinate geometry to four N and three O atoms. There are a spread of Pr–N bond distances ranging from 2.49–2.70 Å. There are a spread of Pr–O bond distances ranging from 2.41–2.48 Å. In the twelfth Pr site, Pr is bonded in a 8-coordinate geometry to five N, two O, and one Cl atom. There are a spread of Pr–N bond distances ranging from 2.37–2.78 Å. Both Pr–O bond lengths are 2.45 Å. The Pr–Cl bond length is 3.20 Å. In the thirteenth Pr site, Pr is bonded in a 6-coordinate geometry to six N and two equivalent O atoms. There are a spread of Pr–N bond distances ranging from 2.43–3.04 Å. Both Pr–O bond lengths are 2.72 Å. In the fourteenth Pr site, Pr is bonded in a 7-coordinate geometry to five N and two O atoms. There are a spread of Pr–N bond distances ranging from 2.42–2.62 Å. There are one shorter (2.64 Å) and one longer (2.79 Å) Pr–O bond lengths. Al is bonded to two equivalent N and two O atoms to form AlN2O2 tetrahedra that share corners with two equivalent SiN3O tetrahedra, edges with two equivalent PrN5O3 hexagonal bipyramids, and edges with two PrN3O4 pentagonal bipyramids. Both Al–N bond lengths are 1.82 Å. There is one shorter (1.79 Å) and one longer (1.80 Å) Al–O bond length. There are eleven inequivalent Si sites. In the first Si site, Si is bonded to three N and one O atom to form SiN3O tetrahedra that share a cornercorner with one AlN2O2 tetrahedra, corners with two SiN3O tetrahedra, an edgeedge with one PrN5O3 hexagonal bipyramid, and an edgeedge with one PrN3O4 pentagonal bipyramid. There are a spread of Si–N bond distances ranging from 1.71–1.73 Å. The Si–O bond length is 1.68 Å. In the second Si site, Si is bonded to three N and one O atom to form SiN3O tetrahedra that share corners with three SiN4 tetrahedra and an edgeedge with one PrN5O3 hexagonal bipyramid. There are a spread of Si–N bond distances ranging from 1.71–1.74 Å. The Si–O bond length is 1.67 Å. In the third Si site, Si is bonded to two equivalent N and two O atoms to form SiN2O2 tetrahedra that share corners with two equivalent SiN3O tetrahedra and edges with two PrN3O4 pentagonal bipyramids. Both Si–N bond lengths are 1.71 Å. There is one shorter (1.67 Å) and one longer (1.69 Å) Si–O bond length. In the fourth Si site, Si is bonded to three N and one O atom to form corner-sharing SiN3O tetrahedra. There is one shorter (1.71 Å) and two longer (1.73 Å) Si–N bond length. The Si–O bond length is 1.69 Å. In the fifth Si site, Si is bonded to three N and one O atom to form SiN3O tetrahedra that share corners with three SiN3O tetrahedra and an edgeedge with one PrN3O4 pentagonal bipyramid. There are a spread of Si–N bond distances ranging from 1.70–1.76 Å. The Si–O bond length is 1.68 Å. In the sixth Si site, Si is bonded to three N and one O atom to form corner-sharing SiN3O tetrahedra. There is two shorter (1.71 Å) and one longer (1.75 Å) Si–N bond length. The Si–O bond length is 1.68 Å. In the seventh Si site, Si is bonded to three N and one O atom to form corner-sharing SiN3O tetrahedra. There are a spread of Si–N bond distances ranging from 1.71–1.74 Å. The Si–O bond length is 1.68 Å. In the eighth Si site, Si is bonded to three N and one O atom to form SiN3O tetrahedra that share a cornercorner with one PrN3O4 pentagonal bipyramid and corners with two equivalent SiN3O tetrahedra. There is one shorter (1.72 Å) and two longer (1.74 Å) Si–N bond length. The Si–O bond length is 1.71 Å. In the ninth Si site, Si is bonded to four N atoms to form SiN4 tetrahedra that share a cornercorner with one PrN3O4 pentagonal bipyramid, corners with two equivalent SiN4 tetrahedra, and edges with two equivalent PrN5O3 hexagonal bipyramids. There are a spread of Si–N bond distances ranging from 1.74–1.76 Å. In the tenth Si site, Si is bonded to three N and one O atom to form SiN3O tetrahedra that share corners with three SiN3O tetrahedra and an edgeedge with one PrN5O3 hexagonal bipyramid. There are a spread of Si–N bond distances ranging from 1.71–1.74 Å. The Si–O bond length is 1.68 Å. In the eleventh Si site, Si is bonded to four N atoms to form SiN4 tetrahedra that share corners with three SiN3O tetrahedra and an edgeedge with one PrN5O3 hexagonal bipyramid. There are a spread of Si–N bond distances ranging from 1.70–1.77 Å. There are twenty inequivalent N sites. In the first N site, N is bonded in a 2-coordinate geometry to three Pr and two Si atoms. In the second N site, N is bonded to two Pr and two equivalent Si atoms to form a mixture of distorted edge and corner-sharing NPr2Si2 tetrahedra. In the third N site, N is bonded in a 5-coordinate geometry to three Pr, one Al, and one Si atom. In the fourth N site, N is bonded to two Pr and two Si atoms to form distorted NPr2Si2 trigonal pyramids that share corners with three NPr2Si2 tetrahedra, corners with three OPr3Si tetrahedra, and a cornercorner with one NPr2Si2 trigonal pyramid. In the fifth N site, N is bonded to two Pr and two Si atoms to form distorted NPr2Si2 trigonal pyramids that share corners with two OPr3Si tetrahedra, corners with four NPr3Si tetrahedra, and a cornercorner with one NPr2Si2 trigonal pyramid. In the sixth N site, N is bonded in a distorted linear geometry to three Pr and two Si atoms. In the seventh N site, N is bonded to two Pr and two equivalent Si atoms to form distorted NPr2Si2 tetrahedra that share corners with two equivalent OPr3Si tetrahedra, corners with six NPr2Si2 trigonal pyramids, and an edgeedge with one NPr2Si2 tetrahedra. In the eighth N site, N is bonded in a 2-coordinate geometry to three Pr and two Si atoms. In the ninth N site, N is bonded in a 2-coordinate geometry to three Pr and two Si atoms. In the tenth N site, N is bonded to two Pr and two equivalent Si atoms to form distorted NPr2Si2 tetrahedra that share corners with six NPr2Si2 trigonal pyramids, an edgeedge with one NPr2Si2 tetrahedra, and edges with two equivalent OPr3Si tetrahedra. In the eleventh N site, N is bonded to four Pr and one Si atom to form distorted NPr4Si square pyramids that share corners with two equivalent NPr3Si2 trigonal bipyramids, a cornercorner with one OPr3Al trigonal pyramid, corners with two equivalent NPr2Si2 trigonal pyramids, edges with four OPr3Si tetrahedra, edges with two equivalent NPr3Si2 trigonal bipyramids, and an edgeedge with one NPr3Si trigonal pyramid. In the twelfth N site, N is bonded to three Pr and two Si atoms to form distorted NPr3Si2 trigonal bipyramids that share a cornercorner with one NPr4Si square pyramid, a cornercorner with one NPr3Si tetrahedra, corners with two OPr3Si tetrahedra, a cornercorner with one NPr3Si trigonal pyramid, an edgeedge with one NPr4Si square pyramid, edges with two OPr3Si tetrahedra, an edgeedge with one NPr3Si2 trigonal bipyramid, an edgeedge with one NPr2Si2 trigonal pyramid, and an edgeedge with one OPr3Si trigonal pyramid. In the thirteenth N site, N is bonded to two Pr and two Si atoms to form distorted NPr2Si2 trigonal pyramids that share a cornercorner with one NPr4Si square pyramid, corners with three OPr3Si tetrahedra, corners with four NPr2Si2 tetrahedra, a cornercorner with one NPr2Si2 trigonal pyramid, an edgeedge with one OPr3Si tetrahedra, and an edgeedge with one NPr3Si2 trigonal bipyramid. In the fourteenth N site, N is bonded to two Pr and two Si atoms to form distorted NPr2Si2 trigonal pyramids that share a cornercorner with one NPr4Si square pyramid, corners with three OPr3Si tetrahedra, corners with four NPr2Si2 tetrahedra, a cornercorner with one NPr2Si2 trigonal pyramid, and an edgeedge with one NPr3Si2 trigonal bipyramid. In the fifteenth N site, N is bonded to three Pr and two Si atoms to form distorted NPr3Si2 trigonal bipyramids that share a cornercorner with one NPr4Si square pyramid, a cornercorner with one NPr3Si tetrahedra, corners with two OPr3Si tetrahedra, corners with two OPr3Al trigonal pyramids, an edgeedge with one NPr4Si square pyramid, an edgeedge with one NPr3Si tetrahedra, an edgeedge with one NPr3Si2 trigonal bipyramid, and edges with two NPr3Si trigonal pyramids. In the sixteenth N site, N is bonded to three Pr and one Si atom to form distorted NPr3Si trigonal pyramids that share corners with two equivalent OPr3Si tetrahedra, corners with two equivalent NPr3Si2 trigonal bipyramids, an edgeedge with one NPr4Si square pyramid, edges with two equivalent NPr3Si2 trigonal bipyramids, and an edgeedge with one OPr3Al trigonal pyramid. In the seventeenth N site, N is bonded to four Pr and one Si atom to form distorted NPr4Si square pyramids that share corners with two equivalent OPr3Si tetrahedra, corners with two equivalent NPr3Si2 trigonal bipyramids, corners with two equivalent NPr2Si2 trigonal pyramids, edges with two equivalent NPr3Si tetrahedra, edges with two equivalent OPr3Si tetrahedra, edges with two

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.84–2.89 Å. In the second Mg site, Mg is bonded in a 3-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.17 Å. In the third Mg site, Mg is bonded in a distorted water-like geometry to two equivalent Si atoms. There are one shorter (2.76 Å) and one longer (2.78 Å) Mg–Si bond lengths. In the fourth Mg site, Mg is bonded to five Si atoms to form distorted edge-sharing MgSi5 square pyramids. There are a spread of Mg–Si bond distances ranging from 2.80–2.82 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–2.96 Å. In the sixth Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.81–3.11 Å. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.84–2.92 Å. In the eighth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.02 Å. In the ninth Mg site, Mg is bonded in a distorted linear geometry to two Si atoms. There are one shorter (2.76 Å) and one longer (2.81 Å) Mg–Si bond lengths. In the tenth Mg site, Mg is bonded in a linear geometry to two Si atoms. Both Mg–Si bond lengths are 2.70 Å. In the eleventh Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–2.93 Å. In the twelfth Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.82–3.13 Å. In the thirteenth Mg site, Mg is bonded in a linear geometry to two Si atoms. There are one shorter (2.64 Å) and one longer (2.68 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted single-bond geometry to one Si atom. The Mg–Si bond length is 2.81 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms. There are two shorter (2.55 Å) and one longer (2.57 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.51 Å. In the third Si site, Si is bonded in a 5-coordinate geometry to five Mg and two equivalent Si atoms. There are one shorter (2.56 Å) and one longer (2.62 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms. There are one shorter (2.53 Å) and two longer (2.57 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms. In the sixth Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. In the seventh Si site, Si is bonded in a 8-coordinate geometry to eight Mg atoms. In the eighth Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Mg7Si4 sheet oriented in the (0, 0, 1) direction. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted trigonal non-coplanar geometry to two Mg and three Si atoms. There are one shorter (3.02 Å) and one longer (3.19 Å) Mg–Mg bond lengths. There are one shorter (2.75 Å) and two longer (2.82 Å) Mg–Si bond lengths. In the second Mg site, Mg is bonded to four Mg and four Si atoms to form distorted MgMg4Si4 tetrahedra that share corners with two equivalent MgSi4 trigonal pyramids, an edgeedge with one MgSi4 trigonal pyramid, and faces with two equivalent MgMg4Si4 tetrahedra. There are a spread of Mg–Mg bond distances ranging from 3.09–3.26 Å. There are a spread of Mg–Si bond distances ranging from 2.68–2.84 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to seven Mg and six Si atoms. There are a spread of Mg–Mg bond distances ranging from 3.00–3.24 Å. There are a spread of Mg–Si bond distances ranging from 2.92–3.17 Å. In the fourth Mg site, Mg is bonded in a 5-coordinate geometry to six Mg and seven Si atoms. The Mg–Mg bond length is 3.35 Å. There are a spread of Mg–Si bond distances ranging from 2.92–3.13 Å. In the fifth Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.18 Å. In the sixth Mg site, Mg is bonded in a 2-coordinate geometry to two Si atoms. There are one shorter (2.79 Å) and one longer (2.88 Å) Mg–Si bond lengths. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–3.08 Å. In the eighth Mg site, Mg is bonded in a distorted L-shaped geometry to two Si atoms. There are one shorter (2.74 Å) and one longer (2.80 Å) Mg–Si bond lengths. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.10 Å. In the tenth Mg site, Mg is bonded to four Si atoms to form distorted MgSi4 trigonal pyramids that share corners with two equivalent MgMg4Si4 tetrahedra, corners with two equivalent MgSi4 trigonal pyramids, and an edgeedge with one MgMg4Si4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.67–3.00 Å. In the eleventh Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.87–3.09 Å. In the twelfth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.85 Å. In the thirteenth Mg site, Mg is bonded in a distorted water-like geometry to one Mg and two equivalent Si atoms. There are one shorter (2.80 Å) and one longer (2.82 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted water-like geometry to two Mg and two equivalent Si atoms. There are one shorter (2.74 Å) and one longer (2.78 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.45 Å) and one longer (2.47 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.48 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to nine Mg atoms. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. Both Si–Si bond lengths are 2.46 Å. In the fifth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. In the sixth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.42 Å. In the seventh Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the eighth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCa4Al10(SiO5)10 by Materials Project

SrCa4Al10(SiO5)10 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Sr–O bond distances ranging from 2.48–2.66 Å. In the second Sr site, Sr is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.66 Å. There are eight inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.60 Å. In the second Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.60 Å. In the third Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.60 Å. In the fourth Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.60 Å. In the fifth Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.60 Å. In the sixth Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.61 Å. In the seventh Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.39–2.60 Å. In the eighth Ca site, Ca is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.61 Å. There are twenty inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–2.00 Å. In the third Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the fourth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the fifth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There is four shorter (1.89 Å) and two longer (1.97 Å) Al–O bond length. In the sixth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the seventh Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the eighth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the ninth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. In the tenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–2.00 Å. In the eleventh Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the twelfth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the thirteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the fourteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. In the fifteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.01 Å. In the sixteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the seventeenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the eighteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. In the nineteenth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. In the twentieth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with two AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.01 Å. There are twenty inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–61°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the ninth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the tenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the eleventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the twelfth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the thirteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fourteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fifteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the sixteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the seventeenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the eighteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–61°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the nineteenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–60°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the twentieth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahe

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu5Sc5(Si5Ir2)4 by Materials Project

Lu5Sc5(Ir2Si5)4 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Lu3+ sites. In the first Lu3+ site, Lu3+ is bonded to eight Si+2.80- atoms to form distorted LuSi8 hexagonal bipyramids that share corners with four equivalent IrSi5 trigonal bipyramids, edges with four equivalent ScSi12 cuboctahedra, faces with two equivalent LuSi8 hexagonal bipyramids, and faces with four equivalent IrSi5 trigonal bipyramids. There are a spread of Lu–Si bond distances ranging from 2.84–3.05 Å. In the second Lu3+ site, Lu3+ is bonded to eight Si+2.80- atoms to form distorted LuSi8 hexagonal bipyramids that share corners with four equivalent IrSi5 trigonal bipyramids, edges with four equivalent ScSi12 cuboctahedra, faces with two equivalent LuSi8 hexagonal bipyramids, and faces with four equivalent IrSi5 trigonal bipyramids. There are a spread of Lu–Si bond distances ranging from 2.85–3.05 Å. In the third Lu3+ site, Lu3+ is bonded to eight Si+2.80- atoms to form distorted LuSi8 hexagonal bipyramids that share corners with four IrSi5 trigonal bipyramids, edges with four equivalent ScSi12 cuboctahedra, faces with two equivalent LuSi8 hexagonal bipyramids, and faces with four IrSi5 trigonal bipyramids. There are a spread of Lu–Si bond distances ranging from 2.85–3.05 Å. In the fourth Lu3+ site, Lu3+ is bonded in a 10-coordinate geometry to ten Si+2.80- atoms. There are a spread of Lu–Si bond distances ranging from 3.14–3.27 Å. There are three inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded in a 10-coordinate geometry to ten Si+2.80- atoms. There are a spread of Sc–Si bond distances ranging from 3.12–3.25 Å. In the second Sc3+ site, Sc3+ is bonded in a 10-coordinate geometry to ten Si+2.80- atoms. There are a spread of Sc–Si bond distances ranging from 3.11–3.24 Å. In the third Sc3+ site, Sc3+ is bonded to twelve Si+2.80- atoms to form distorted ScSi12 cuboctahedra that share corners with eight IrSi5 trigonal bipyramids, edges with eight LuSi8 hexagonal bipyramids, faces with two equivalent ScSi12 cuboctahedra, and faces with four IrSi5 trigonal bipyramids. There are a spread of Sc–Si bond distances ranging from 2.80–3.23 Å. There are four inequivalent Ir+3.25+ sites. In the first Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent ScSi12 cuboctahedra, corners with two equivalent LuSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one ScSi12 cuboctahedra, and faces with two equivalent LuSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.37–2.48 Å. In the second Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent ScSi12 cuboctahedra, corners with two equivalent LuSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one ScSi12 cuboctahedra, and faces with two equivalent LuSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.36–2.48 Å. In the third Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent ScSi12 cuboctahedra, corners with two equivalent LuSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one ScSi12 cuboctahedra, and faces with two equivalent LuSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.36–2.47 Å. In the fourth Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent ScSi12 cuboctahedra, corners with two equivalent LuSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one ScSi12 cuboctahedra, and faces with two equivalent LuSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.36–2.46 Å. There are eleven inequivalent Si+2.80- sites. In the first Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Lu3+, four equivalent Sc3+, two equivalent Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.29 Å. In the second Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Lu3+, four equivalent Sc3+, two equivalent Ir+3.25+, and one Si+2.80- atom. In the third Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to four Lu3+, two equivalent Sc3+, two Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.31 Å. In the fourth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Lu3+, three Sc3+, and two Ir+3.25+ atoms. In the fifth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Lu3+, three Sc3+, and two Ir+3.25+ atoms. In the sixth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Lu3+, three Sc3+, and two Ir+3.25+ atoms. In the seventh Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to four Lu3+, one Sc3+, and two Ir+3.25+ atoms. In the eighth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two Lu3+, two equivalent Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. There are one shorter (2.65 Å) and one longer (2.68 Å) Si–Si bond lengths. In the ninth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to one Lu3+, three Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. There are one shorter (2.67 Å) and one longer (2.68 Å) Si–Si bond lengths. In the tenth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to one Lu3+, three Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. In the eleventh Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to one Lu3+, three Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.98 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.82–2.94 Å. In the third Mg site, Mg is bonded in a distorted water-like geometry to two equivalent Si atoms. There are one shorter (2.74 Å) and one longer (2.77 Å) Mg–Si bond lengths. In the fourth Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.07 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to one Mg and three Si atoms. The Mg–Mg bond length is 3.10 Å. There are a spread of Mg–Si bond distances ranging from 2.74–2.91 Å. In the sixth Mg site, Mg is bonded in a 5-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–3.17 Å. In the seventh Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–3.16 Å. In the eighth Mg site, Mg is bonded in a water-like geometry to two equivalent Si atoms. There are one shorter (2.68 Å) and one longer (2.69 Å) Mg–Si bond lengths. In the ninth Mg site, Mg is bonded in a distorted linear geometry to two equivalent Mg and two Si atoms. There are one shorter (3.13 Å) and one longer (3.14 Å) Mg–Mg bond lengths. There are one shorter (2.73 Å) and one longer (2.89 Å) Mg–Si bond lengths. In the tenth Mg site, Mg is bonded in a distorted linear geometry to two equivalent Mg and two Si atoms. There are one shorter (3.15 Å) and one longer (3.17 Å) Mg–Mg bond lengths. There are one shorter (2.71 Å) and one longer (2.80 Å) Mg–Si bond lengths. In the eleventh Mg site, Mg is bonded in a 11-coordinate geometry to six Mg and five Si atoms. The Mg–Mg bond length is 3.07 Å. There are a spread of Mg–Si bond distances ranging from 2.71–3.06 Å. In the twelfth Mg site, Mg is bonded in a trigonal non-coplanar geometry to one Mg and three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.79–2.82 Å. In the thirteenth Mg site, Mg is bonded in a linear geometry to two Si atoms. There are one shorter (2.70 Å) and one longer (2.72 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in an L-shaped geometry to two Si atoms. Both Mg–Si bond lengths are 2.76 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.46–2.50 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.43 Å) and one longer (2.47 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 7-coordinate geometry to five Mg and two equivalent Si atoms. There are one shorter (2.44 Å) and one longer (2.49 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 8-coordinate geometry to eight Mg atoms. In the fifth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the sixth Si site, Si is bonded in a 8-coordinate geometry to four Mg and four Si atoms. The Si–Si bond length is 2.69 Å. In the seventh Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. In the eighth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.86–3.17 Å. In the second Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.20 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–2.90 Å. In the fourth Mg site, Mg is bonded in a 3-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.09 Å. In the fifth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.08 Å. In the sixth Mg site, Mg is bonded in a 2-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.70–3.11 Å. In the seventh Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.66–3.14 Å. In the eighth Mg site, Mg is bonded in a 2-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.23 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.80 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.97 Å. In the eleventh Mg site, Mg is bonded in a 2-coordinate geometry to two Si atoms. There are one shorter (2.85 Å) and one longer (2.91 Å) Mg–Si bond lengths. In the twelfth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–2.89 Å. In the thirteenth Mg site, Mg is bonded in a 5-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–3.13 Å. In the fourteenth Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.17 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to six Mg and one Si atom. The Si–Si bond length is 2.49 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.56 Å. In the third Si site, Si is bonded in a 10-coordinate geometry to eight Mg and two Si atoms. The Si–Si bond length is 2.52 Å. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.47 Å) and one longer (2.48 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. In the sixth Si site, Si is bonded in a 10-coordinate geometry to ten Mg atoms. In the seventh Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the eighth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca8Be5Al3(Si9O28)2 by Materials Project

Ca8Be5Al3(Si9O28)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are four inequivalent Ca sites. In the first Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.66 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.70 Å. In the third Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.71 Å. In the fourth Ca site, Ca is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.70 Å. There are three inequivalent Be sites. In the first Be site, Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.67 Å) Be–O bond length. In the second Be site, Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with three SiO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.62–1.70 Å. In the third Be site, Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with three SiO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.62–1.72 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the third Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. There are eleven inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with three SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.64 Å) Si–O bond length. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra and corners with three SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.64 Å) Si–O bond length. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one BeO4 tetrahedra, a cornercorner with one AlO4 tetrahedra, and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.72 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with two AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two BeO4 tetrahedra and corners with two SiO4 tetrahedra. There is two shorter (1.64 Å) and two longer (1.67 Å) Si–O bond length. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent BeO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the ninth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the tenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the eleventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. There are twenty-eight inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to two Ca, one Be, and one Si atom. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to two Ca, one Be, and one Si atom. In the seventh O site, O is bonded in a 3-coordinate geometry to one Ca, one Be, and one Si atom. In the eighth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the ninth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the tenth O site, O is bonded in a 3-coordinate geometry to one Ca, one Al, and one Si atom. In the eleventh O site, O is bonded in a distorted trigonal planar geometry to one Ca, one Be, and one Si atom. In the twelfth O site, O is bonded in a 3-coordinate geometry to one Ca, one Be, and one Si atom. In the thirteenth O site, O is bonded in a 3-coordinate geometry to one Ca, one Be, and one Si atom. In the fourteenth O site, O is bonded in a 3-coordinate geometry to one Ca, one Be, and one Si atom. In the fifteenth O site, O is bonded in a distorted bent 120 degrees geometry to two Ca and two Si atoms. In the sixteenth O site, O is bonded in a distorted bent 120 degrees geometry to two Ca and two Si atoms. In the seventeenth O site, O is bonded in a trigonal planar geometry to two Ca and one Si atom. In the eighteenth O site, O is bonded in a trigonal planar geometry to two Ca and one Si atom. In the nineteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twentieth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-third O site, O is bonded in a 2-coordinate geometry to one Ca, one Be, and one Si atom. In the twenty-fourth O site, O is bonded in a 2-coordinate geometry to one Ca, one Al, and one Si atom. In the twenty-fifth O site, O is bonded in a 2-coordinate geometry to one Ca, one Al, and one Si atom. In the twenty-sixth O site, O is bonded in a 2-coordinate geometry to one Ca, one Al, and one Si atom. In the twenty-seventh O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Be atom. In the twenty-eighth O site, O is bonded in a distorted trigonal planar geometry to two Ca and one Be atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg7Si4 by Materials Project

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted trigonal non-coplanar geometry to one Mg and three Si atoms. The Mg–Mg bond length is 3.01 Å. There are a spread of Mg–Si bond distances ranging from 2.75–2.85 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and four Si atoms. Both Mg–Mg bond lengths are 3.30 Å. There are a spread of Mg–Si bond distances ranging from 2.69–2.95 Å. In the third Mg site, Mg is bonded in a 5-coordinate geometry to seven Mg and six Si atoms. There are a spread of Mg–Mg bond distances ranging from 2.98–3.19 Å. There are a spread of Mg–Si bond distances ranging from 2.92–3.24 Å. In the fourth Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.89–3.12 Å. In the fifth Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.79–3.04 Å. In the sixth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.03 Å. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.87–3.13 Å. In the eighth Mg site, Mg is bonded in a 2-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.70–3.03 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.00 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–2.95 Å. In the eleventh Mg site, Mg is bonded in a 5-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.86–3.15 Å. In the twelfth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.88 Å. In the thirteenth Mg site, Mg is bonded in a 2-coordinate geometry to one Mg and two equivalent Si atoms. There are one shorter (2.85 Å) and one longer (2.89 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted bent 120 degrees geometry to one Mg and two equivalent Si atoms. There are one shorter (2.75 Å) and one longer (2.76 Å) Mg–Si bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.44 Å) and one longer (2.50 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.54 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to nine Mg atoms. In the fourth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.44 Å) and one longer (2.46 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. In the sixth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.44 Å. In the seventh Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms.

36 MATERIALS SCIENCE↗