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DOE OSTI2020

Materials Data on SrCaMg30O32 by Materials Project

SrCaMg30O32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.24 Å) and four longer (2.34 Å) Sr–O bond lengths. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.11 Å) and four longer (2.28 Å) Ca–O bond lengths. There are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.03–2.18 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.98 Å) and four longer (2.19 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.13 Å) and two longer (2.17 Å) Mg–O bond lengths. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.18 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SrO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.09–2.22 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.15–2.18 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 2.13–2.19 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SrO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Mg–O bond distances ranging from 2.11–2.20 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form OCaMg5 octahedra that share corners with six OSrMg5 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the second O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the third O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. Both O–Mg bond lengths are 2.18 Å. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. Both O–Mg bond lengths are 2.18 Å. In the fifth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of O–Mg bond distances ranging from 2.03–2.19 Å. In the sixth O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. All O–Mg bond lengths are 2.20 Å. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (2.13 Å) and two longer (2.18 Å) O–Mg bond lengths. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the tenth O2- site, O2- is bonded to one Sr2+, one Ca2+, and four equivalent Mg2+ atoms to form OSrCaMg4 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the eleventh O2- site, O2- is bonded to one Sr2+, one Ca2+, and four equivalent Mg2+ atoms to form OSrCaMg4 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. All O–Mg bond lengths are 2.22 Å. In the twelfth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the thirteenth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.09 Å) and two longer (2.16 Å) O–Mg bond lengths. In the fourteenth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifteenth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. The O–Mg bond length is 2.18 Å. In the sixteenth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (2.13 Å) and three longer (2.18 Å) O–Mg bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCaMg30O32 by Materials Project

SrCaMg30O32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.32 Å) and two longer (2.33 Å) Sr–O bond lengths. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.24 Å) and two longer (2.27 Å) Ca–O bond lengths. There are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with two equivalent CaO6 octahedra, corners with two equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.00–2.21 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.05 Å) and four longer (2.17 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.11–2.15 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.98 Å) and four longer (2.19 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SrO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. There are a spread of Mg–O bond distances ranging from 2.15–2.18 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Mg–O bond lengths are 2.16 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Mg–O bond distances ranging from 2.13–2.19 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SrO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are a spread of Mg–O bond distances ranging from 2.11–2.21 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form OCaMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the second O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the third O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the fifth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the sixth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.15 Å) and two longer (2.19 Å) O–Mg bond lengths. In the seventh O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. The O–Mg bond length is 2.00 Å. In the eighth O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. Both O–Mg bond lengths are 2.21 Å. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the tenth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSrMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the eleventh O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are one shorter (2.08 Å) and two longer (2.19 Å) O–Mg bond lengths. In the twelfth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of corner and edge-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of O–Mg bond distances ranging from 2.08–2.19 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCaMg14O16 by Materials Project

SrCaMg14O16 is alpha Po-derived structured and crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with two equivalent CaO6 octahedra, corners with two equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Sr–O bond distances ranging from 2.22–2.37 Å. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with two equivalent CaO6 octahedra, corners with two equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ca–O bond distances ranging from 2.14–2.31 Å. There are ten inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.04–2.22 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.98–2.23 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.17–2.25 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.17–2.25 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Mg–O bond distances ranging from 2.16–2.22 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.11–2.23 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.09–2.26 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.11–2.23 Å. In the ninth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.09–2.26 Å. In the tenth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, an edgeedge with one SrO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.10–2.25 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form OCaMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the second O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the third O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OCaMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. Both O–Mg bond lengths are 2.24 Å. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and four Mg2+ atoms to form OCa2Mg4 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O2- site, O2- is bonded to two equivalent Sr2+ and four Mg2+ atoms to form OSr2Mg4 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OSrMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSr2Mg4 octahedra and edges with twelve OSrMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the ninth O2- site, O2- is bonded to one Sr2+, one Ca2+, and four Mg2+ atoms to form OSrCaMg4 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the tenth O2- site, O2- is bonded to one Sr2+, one Ca2+, and four Mg2+ atoms to form OSrCaMg4 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. Both O–Mg bond lengths are 2.25 Å. In the eleventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSrCaMg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCaMg14O16 by Materials Project

SrCaMg14O16 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.22 Å) and four longer (2.36 Å) Sr–O bond lengths. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.22 Å) and four longer (2.27 Å) Ca–O bond lengths. There are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SrO6 octahedra, corners with two equivalent CaO6 octahedra, corners with two equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.01–2.22 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.14–2.23 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.14–2.23 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 2.11–2.26 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent SrO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 2.11–2.26 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, an edgeedge with one SrO6 octahedra, an edgeedge with one CaO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. There are a spread of Mg–O bond distances ranging from 2.17–2.22 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. Both O–Mg bond lengths are 2.22 Å. In the third O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are two shorter (2.21 Å) and two longer (2.22 Å) O–Mg bond lengths. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. In the fifth O2- site, O2- is bonded to two equivalent Ca2+ and four Mg2+ atoms to form OCa2Mg4 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the sixth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OCa2Mg4 octahedra and edges with twelve OCaMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to two equivalent Sr2+ and four Mg2+ atoms to form OSr2Mg4 octahedra that share corners with six OMg6 octahedra and edges with twelve OSrMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to one Ca2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OCaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. Both O–Mg bond lengths are 2.17 Å. In the ninth O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. The O–Mg bond length is 2.01 Å. In the tenth O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are one shorter (2.01 Å) and two longer (2.21 Å) O–Mg bond lengths.

36 MATERIALS SCIENCE↗