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DOE OSTI2020

Materials Data on RbMgBO3 by Materials Project

RbMgBO3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Rb1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (2.88 Å) and three longer (2.95 Å) Rb–O bond lengths. Mg2+ is bonded to six equivalent O2- atoms to form distorted corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are three shorter (2.14 Å) and three longer (2.19 Å) Mg–O bond lengths. B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.39 Å. O2- is bonded in a 1-coordinate geometry to two equivalent Rb1+, two equivalent Mg2+, and one B3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg6BO7 by Materials Project

RbMg6BO7 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Rb is bonded to six O atoms to form RbO6 octahedra that share corners with four equivalent RbO6 octahedra, edges with four equivalent MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 1°. There are four shorter (2.51 Å) and two longer (2.59 Å) Rb–O bond lengths. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with five MgO5 square pyramids, edges with four equivalent RbO6 octahedra, and edges with four equivalent MgO6 octahedra. There are one shorter (1.98 Å) and four longer (2.51 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with five MgO5 square pyramids and edges with four equivalent MgO6 octahedra. There are one shorter (1.99 Å) and four longer (2.51 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded in a 2-coordinate geometry to four O atoms. There are a spread of Mg–O bond distances ranging from 1.90–2.58 Å. In the fourth Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four equivalent MgO6 octahedra, edges with two equivalent RbO6 octahedra, edges with four equivalent MgO6 octahedra, and edges with four MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 3–26°. There are a spread of Mg–O bond distances ranging from 1.90–2.57 Å. B is bonded in a linear geometry to two O atoms. Both B–O bond lengths are 1.31 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Rb, four equivalent Mg, and one B atom. In the second O site, O is bonded in a distorted single-bond geometry to one Rb, four equivalent Mg, and one B atom. In the third O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra and edges with four equivalent ORb2Mg4 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fourth O site, O is bonded to two equivalent Rb and four Mg atoms to form ORb2Mg4 octahedra that share corners with four equivalent ORb2Mg4 octahedra and edges with six OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. In the fifth O site, O is bonded in a square co-planar geometry to four Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO31 by Materials Project

RbMg30BO31 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded to six O atoms to form distorted RbO6 octahedra that share corners with four MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Rb–O bond distances ranging from 2.41–2.86 Å. There are sixteen inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent RbO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 1.97–2.25 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Mg–O bond distances ranging from 1.98–2.28 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent RbO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with eight MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.93–2.26 Å. In the fourth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, and edges with six MgO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Mg–O bond distances ranging from 1.98–2.21 Å. In the fifth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.09–2.16 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.08–2.20 Å. In the seventh Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one RbO6 octahedra, edges with seven MgO6 octahedra, an edgeedge with one MgO5 square pyramid, and an edgeedge with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 3–35°. There are a spread of Mg–O bond distances ranging from 2.03–2.45 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with eight MgO6 octahedra, edges with two MgO5 square pyramids, and an edgeedge with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Mg–O bond distances ranging from 2.07–2.23 Å. In the ninth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, corners with three MgO5 square pyramids, a cornercorner with one MgO5 trigonal bipyramid, an edgeedge with one RbO6 octahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Mg–O bond distances ranging from 2.05–2.20 Å. In the tenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 trigonal bipyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.07–2.21 Å. In the eleventh Mg site, Mg is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 2.02–2.64 Å. In the twelfth Mg site, Mg is bonded to six O 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 2.07–2.26 Å. In the thirteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, an edgeedge with one RbO6 octahedra, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Mg–O bond distances ranging from 2.09–2.26 Å. In the fourteenth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with two MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Mg–O bond distances ranging from 2.08–2.17 Å. In the fifteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one RbO6 octahedra, and edges with nine MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Mg–O bond distances ranging from 2.09–2.24 Å. In the sixteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with eight MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 2–15°. There are a spread of Mg–O bond distances ranging from 2.09–2.30 Å. B is bonded in a distorted bent 150 degrees geometry to two equivalent O atoms. Both B–O bond lengths are 1.41 Å. There are seventeen inequivalent O sites. In the first O site, O is bonded to one Rb and five Mg atoms to form a mixture of edge and corner-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the second O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six ORbMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the third O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the fifth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with four ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 5–10°. In the sixth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with nine ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 2–9°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with nine ORbMg5 octahedra, and edges with two OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 2–11°. In the tenth O site, O is bonded in a 1-coordinate geometry to one Rb, four Mg, and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the twelfth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–4°. In the thirteenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourteenth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with ten ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. In the fifteenth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with four ORbMg5 octahedra, corners with two OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. In the sixteenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. In the seventeenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–4°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg14BO15 by Materials Project

RbMg14BO15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded in a 2-coordinate geometry to five O atoms. There are a spread of Rb–O bond distances ranging from 2.33–2.80 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Mg–O bond distances ranging from 2.03–2.26 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, and edges with ten MgO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Mg–O bond distances ranging from 2.00–2.31 Å. In the third Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–31°. There are a spread of Mg–O bond distances ranging from 1.99–2.35 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with seven MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Mg–O bond distances ranging from 2.04–2.39 Å. In the fifth Mg site, Mg is bonded in a distorted T-shaped geometry to three O atoms. There are one shorter (2.06 Å) and two longer (2.09 Å) Mg–O bond lengths. In the sixth Mg site, Mg is bonded to six O atoms to form a mixture of distorted edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–23°. There are a spread of Mg–O bond distances ranging from 2.07–2.56 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Mg–O bond distances ranging from 1.99–2.27 Å. In the eighth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Mg–O bond distances ranging from 2.05–2.26 Å. In the ninth Mg site, Mg is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.94–2.64 Å. In the tenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 4–9°. There are a spread of Mg–O bond distances ranging from 2.01–2.26 Å. B is bonded in a distorted trigonal planar geometry to three O atoms. There is two shorter (1.44 Å) and one longer (1.50 Å) B–O bond length. There are eleven inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form OMg5 trigonal bipyramids that share a cornercorner with one OMg5B octahedra, corners with two equivalent OMg5 trigonal bipyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to one Rb and five Mg atoms to form distorted ORbMg5 octahedra that share corners with four ORbMg5 octahedra and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. In the third O site, O is bonded to five Mg and one B atom to form distorted OMg5B octahedra that share corners with four ORbMg5 octahedra, a cornercorner with one OMg5 trigonal bipyramid, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with four OMg6 octahedra, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–16°. In the fifth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with eight ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the sixth O site, O is bonded in a 5-coordinate geometry to two equivalent Rb and three Mg atoms. In the seventh O site, O is bonded in a square co-planar geometry to four Mg atoms. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra and edges with ten ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg5B octahedra, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–5°. In the tenth O site, O is bonded in a distorted single-bond geometry to one Rb, four Mg, and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 1–4°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg14BO15 by Materials Project

RbMg14BO15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Rb–O bond distances ranging from 2.38–2.82 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with two equivalent MgO6 octahedra, edges with four equivalent MgO5 square pyramids, and edges with six MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. There are a spread of Mg–O bond distances ranging from 2.02–2.16 Å. In the second Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with four MgO5 trigonal bipyramids, edges with four equivalent MgO5 square pyramids, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of Mg–O bond distances ranging from 2.00–2.18 Å. In the third Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four equivalent MgO6 octahedra, a cornercorner with one MgO5 square pyramid, corners with three MgO5 trigonal bipyramids, an edgeedge with one MgO6 octahedra, and edges with three MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 4–32°. There are a spread of Mg–O bond distances ranging from 1.99–2.53 Å. In the fourth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share a cornercorner with one MgO6 octahedra, corners with four equivalent MgO5 square pyramids, corners with three MgO5 trigonal bipyramids, edges with three MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. There are a spread of Mg–O bond distances ranging from 1.99–2.16 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, a cornercorner with one MgO5 trigonal bipyramid, edges with four MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 10°. There are a spread of Mg–O bond distances ranging from 1.94–2.27 Å. In the sixth Mg site, Mg is bonded in a distorted square co-planar geometry to four O atoms. There are a spread of Mg–O bond distances ranging from 2.01–2.21 Å. In the seventh Mg site, Mg is bonded to five O atoms to form MgO5 trigonal bipyramids that share corners with three MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with four MgO5 trigonal bipyramids, edges with two equivalent MgO6 octahedra, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–70°. There are a spread of Mg–O bond distances ranging from 2.07–2.16 Å. In the eighth Mg site, Mg is bonded to five O atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO5 square pyramids, corners with four MgO5 trigonal bipyramids, edges with two equivalent MgO6 octahedra, and edges with four equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 2.12–2.28 Å. In the ninth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share a cornercorner with one MgO5 square pyramid, corners with four MgO5 trigonal bipyramids, edges with five MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 2.03–2.28 Å. In the tenth Mg site, Mg is bonded to five O atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with five MgO5 trigonal bipyramids, an edgeedge with one MgO6 octahedra, an edgeedge with one MgO5 square pyramid, and edges with four MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 77°. There are a spread of Mg–O bond distances ranging from 2.00–2.22 Å. B is bonded in a bent 150 degrees geometry to two equivalent O atoms. Both B–O bond lengths are 1.45 Å. There are eleven inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form distorted OMg5 square pyramids that share a cornercorner with one ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with two equivalent ORb2Mg3 trigonal bipyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with two equivalent ORbMg5 octahedra, a cornercorner with one OMg5 square pyramid, corners with four OMg5 trigonal bipyramids, edges with four OMg6 octahedra, and edges with four equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 6°. In the third O site, O is bonded to five Mg atoms to form OMg5 trigonal bipyramids that share corners with two equivalent ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with two equivalent OMg5 trigonal bipyramids, edges with two equivalent OMg6 octahedra, and edges with four equivalent OMg5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, a cornercorner with one OMg5 trigonal bipyramid, edges with three OMg6 octahedra, edges with three OMg5 square pyramids, and an edgeedge with one ORb2Mg3 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 1–5°. In the fifth O site, O is bonded to five Mg atoms to form distorted OMg5 trigonal bipyramids that share corners with four OMg6 octahedra, corners with five OMg5 trigonal bipyramids, edges with two equivalent ORbMg5 octahedra, and edges with two equivalent OMg5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 3–76°. In the sixth O site, O is bonded to two equivalent Rb and three Mg atoms to form ORb2Mg3 trigonal bipyramids that share corners with three ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with four OMg5 trigonal bipyramids, and edges with two equivalent OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–65°. In the seventh O site, O is bonded in a distorted square co-planar geometry to four Mg atoms. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with two equivalent OMg6 octahedra, corners with two equivalent OMg5 square pyramids, corners with three OMg5 trigonal bipyramids, edges with eight ORbMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the ninth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with two equivalent OMg6 octahedra, corners with two equivalent OMg5 square pyramids, corners with two equivalent OMg5 trigonal bipyramids, and edges with six OMg6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the tenth O site, O is bonded in a 1-coordinate geometry to one Rb, three Mg, and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, corners with two equivalent OMg5 trigonal bipyramids, edges with five ORbMg5 octahedra, edges with three OMg5 square pyramids, and an edgeedge with one OMg5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 3–11°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO32 by Materials Project

RbMg30BO32 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded to six O2- atoms to form distorted RbO6 octahedra that share corners with four equivalent MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.43 Å) and two longer (2.83 Å) Rb–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 RbO6 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 1.95–2.24 Å. In the second 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 2.04–2.22 Å. 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 two shorter (2.10 Å) and four longer (2.14 Å) Mg–O bond lengths. In the fourth 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 two shorter (2.08 Å) and four longer (2.16 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one RbO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–33°. There are a spread of Mg–O bond distances ranging from 2.04–2.43 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 octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.08–2.22 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 RbO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Mg–O bond distances ranging from 2.09–2.23 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Mg–O bond distances ranging from 2.09–2.21 Å. B3+ is bonded in a linear geometry to two equivalent O2- atoms. Both B–O bond lengths are 1.35 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form ORbMg5 octahedra that share corners with four ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with ten ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the second O2- site, O2- is bonded to five Mg2+ atoms to form distorted OMg5 square pyramids that share corners with four ORbMg5 octahedra, corners with three equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. In the third 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 0–6°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. In the fifth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra, edges with nine ORbMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–9°. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, four equivalent Mg2+, and one B3+ atom. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten ORbMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg14BO15 by Materials Project

RbMg14BO15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Rb–O bond distances ranging from 2.47–2.80 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted see-saw-like geometry to four O atoms. There are two shorter (1.95 Å) and two longer (2.16 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, edges with six MgO6 octahedra, and edges with six MgO5 square pyramids. The corner-sharing octahedral tilt angles are 1°. There are a spread of Mg–O bond distances ranging from 2.00–2.11 Å. In the third Mg site, Mg is bonded to five O atoms to form distorted MgO5 square pyramids that share corners with two MgO6 octahedra, corners with four equivalent MgO5 square pyramids, an edgeedge with one MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 8–58°. There are a spread of Mg–O bond distances ranging from 2.11–2.50 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four equivalent MgO6 octahedra, a cornercorner with one MgO5 square pyramid, edges with four MgO6 octahedra, and edges with five MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 4–11°. There are a spread of Mg–O bond distances ranging from 2.08–2.21 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, a cornercorner with one MgO5 square pyramid, edges with four MgO6 octahedra, and edges with six MgO5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Mg–O bond distances ranging from 1.97–2.28 Å. In the sixth Mg site, Mg is bonded in a distorted T-shaped geometry to three O atoms. There is one shorter (1.96 Å) and two longer (2.00 Å) Mg–O bond length. In the seventh Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with three MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with four MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.05–2.09 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four MgO5 square pyramids, edges with two equivalent MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Mg–O bond distances ranging from 2.16–2.21 Å. In the ninth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO5 square pyramids, edges with five MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 2.05–2.20 Å. In the tenth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with five MgO5 square pyramids, edges with five MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. There are a spread of Mg–O bond distances ranging from 2.01–2.20 Å. B is bonded in a distorted single-bond geometry to five O atoms. There are a spread of B–O bond distances ranging from 1.47–2.18 Å. There are eleven inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share a cornercorner with one ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with two equivalent ORb2Mg3 trigonal bipyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with two equivalent ORbMg5 octahedra, a cornercorner with one OMg5 square pyramid, corners with four OMg4B trigonal bipyramids, edges with four OMg6 octahedra, and edges with four equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the third O site, O is bonded to four Mg and one B atom to form distorted OMg4B trigonal bipyramids that share corners with two equivalent ORbMg5 octahedra, corners with two equivalent OMg4B trigonal bipyramids, edges with four OMg4B2 octahedra, and edges with four equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 8°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, a cornercorner with one OMg5 square pyramid, edges with four OMg6 octahedra, edges with two equivalent OMg5 square pyramids, and an edgeedge with one ORb2Mg3 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 4–25°. In the fifth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share a cornercorner with one OMg6 octahedra, corners with four equivalent OMg5 square pyramids, edges with six ORbMg5 octahedra, and edges with two equivalent OMg4B trigonal bipyramids. The corner-sharing octahedral tilt angles are 2°. In the sixth O site, O is bonded to two equivalent Rb and three Mg atoms to form ORb2Mg3 trigonal bipyramids that share corners with three ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, corners with two equivalent ORb2Mg3 trigonal bipyramids, and edges with two equivalent OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–57°. In the seventh O site, O is bonded in a 5-coordinate geometry to five Mg atoms. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, a cornercorner with one ORb2Mg3 trigonal bipyramid, edges with eight ORbMg5 octahedra, and edges with four OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–4°. In the ninth O site, O is bonded to four Mg and two equivalent B atoms to form OMg4B2 octahedra that share corners with four OMg6 octahedra, edges with six OMg6 octahedra, edges with two equivalent OMg5 square pyramids, and edges with two equivalent OMg4B trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–4°. In the tenth O site, O is bonded in a 5-coordinate geometry to one Rb and four Mg atoms. In the eleventh O site, O is bonded to five Mg and one B atom to form OMg5B octahedra that share corners with four equivalent OMg5B octahedra, edges with seven ORbMg5 octahedra, edges with three OMg5 square pyramids, and an edgeedge with one OMg4B trigonal bipyramid. The corner-sharing octahedra tilt angles range from 3–11°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg6BO7 by Materials Project

RbMg6BO7 crystallizes in the tetragonal P4mm space group. The structure is two-dimensional and consists of one RbMg6BO7 sheet oriented in the (0, 0, 1) direction. Rb is bonded in a 4-coordinate geometry to four equivalent O atoms. All Rb–O bond lengths are 2.68 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to five O atoms to form a mixture of distorted edge and corner-sharing MgO5 square pyramids. There are one shorter (2.03 Å) and four longer (2.07 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to five O atoms to form a mixture of edge and corner-sharing MgO5 square pyramids. There are four shorter (2.02 Å) and one longer (2.11 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded in a T-shaped geometry to three O atoms. There are two shorter (2.02 Å) and one longer (2.23 Å) Mg–O bond lengths. In the fourth Mg site, Mg is bonded to five O atoms to form MgO5 trigonal bipyramids that share corners with two equivalent MgO5 square pyramids, corners with four equivalent MgO5 trigonal bipyramids, edges with two equivalent BO5 square pyramids, and edges with four equivalent MgO5 trigonal bipyramids. There are a spread of Mg–O bond distances ranging from 1.95–2.13 Å. B is bonded to five O atoms to form distorted BO5 square pyramids that share corners with four equivalent BO5 square pyramids and edges with four equivalent MgO5 trigonal bipyramids. There is one shorter (1.44 Å) and four longer (2.04 Å) B–O bond length. There are five inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form distorted OMg5 trigonal bipyramids that share corners with twelve OMg5 trigonal bipyramids and edges with four equivalent OMg4B square pyramids. In the second O site, O is bonded to five Mg atoms to form a mixture of edge and corner-sharing OMg5 square pyramids. In the third O site, O is bonded to four equivalent Mg and one B atom to form OMg4B square pyramids that share corners with four equivalent OMg4B square pyramids and edges with eight OMg5 trigonal bipyramids. In the fourth O site, O is bonded to two equivalent Rb, one Mg, and two equivalent B atoms to form distorted ORb2MgB2 trigonal bipyramids that share corners with six OMg5 trigonal bipyramids, edges with two equivalent OMg4B square pyramids, and edges with four equivalent ORb2MgB2 trigonal bipyramids. In the fifth O site, O is bonded to five Mg atoms to form a mixture of edge and corner-sharing OMg5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO32 by Materials Project

RbMg30BO32 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded to six O2- atoms to form RbO6 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 (2.41 Å) and two longer (2.42 Å) Rb–O bond lengths. There are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with two equivalent RbO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent BO6 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 1.87–2.56 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent RbO6 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 (1.92 Å) and four longer (2.20 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 a spread of Mg–O bond distances ranging from 2.08–2.17 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent BO6 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 (2.13 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 RbO6 octahedra, an edgeedge with one BO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–20°. There are a spread of Mg–O bond distances ranging from 2.13–2.20 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 0–3°. There are four shorter (2.14 Å) and two longer (2.19 Å) Mg–O bond lengths. 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 RbO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Mg–O bond distances ranging from 2.12–2.21 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 BO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–19°. There are a spread of Mg–O bond distances ranging from 2.09–2.21 Å. B3+ is bonded to six O2- atoms to form BO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.72 Å) and two longer (2.23 Å) B–O bond length. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form ORbMg5 octahedra that share corners with six ORbMg5 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 six Mg2+ atoms to form OMg6 octahedra that share corners with six ORbMg5 octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the third O2- site, O2- is bonded to five Mg2+ and one B3+ atom to form a mixture of edge and corner-sharing OMg5B octahedra. The corner-sharing octahedra tilt angles range from 0–1°. 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 ten ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fifth O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted edge and corner-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. The O–Mg bond length is 2.56 Å. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. There are two shorter (2.13 Å) and two longer (2.21 Å) O–Mg bond lengths. In the eighth 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 0–7°. In the ninth 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°. In the tenth O2- site, O2- is bonded in a 6-coordinate geometry to five Mg2+ and one B3+ atom. Both O–Mg bond lengths are 2.21 Å. In the eleventh O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form a mixture of distorted edge and corner-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are a spread of O–Mg bond distances ranging from 1.87–2.21 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg6BO8 by Materials Project

RbMg6BO8 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded to six O2- atoms to form RbO6 octahedra that share corners with four equivalent RbO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.44 Å) and two longer (2.62 Å) Rb–O bond lengths. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent RbO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.97 Å) and four longer (2.44 Å) Mg–O bond lengths. In the second 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 two shorter (1.97 Å) and four longer (2.44 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent RbO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–27°. There are a spread of Mg–O bond distances ranging from 1.91–2.51 Å. B3+ is bonded in a linear geometry to two equivalent O2- atoms. Both B–O bond lengths are 1.32 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, four equivalent Mg2+, and one B3+ atom. In the second O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with four equivalent ORb2Mg4 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to two equivalent Rb1+ and four Mg2+ atoms to form ORb2Mg4 octahedra that share corners with four equivalent ORb2Mg4 octahedra and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded in a distorted square co-planar geometry to four Mg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO31 by Materials Project

RbMg30BO31 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Rb is bonded in a 5-coordinate geometry to five O atoms. There are four shorter (2.44 Å) and one longer (2.70 Å) Rb–O bond lengths. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.95–2.21 Å. In the second Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four equivalent MgO6 octahedra, corners with four equivalent MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are one shorter (2.00 Å) and four longer (2.19 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.06–2.20 Å. In the fourth Mg site, Mg is bonded to six O atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mg–O bond distances ranging from 1.98–2.39 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Mg–O bond distances ranging from 2.11–2.23 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with nine MgO6 octahedra, and edges with three MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Mg–O bond distances ranging from 2.12–2.17 Å. In the seventh Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are a spread of Mg–O bond distances ranging from 1.97–2.17 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Mg–O bond distances ranging from 2.09–2.27 Å. In the ninth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 4–7°. There are a spread of Mg–O bond distances ranging from 2.10–2.20 Å. In the tenth Mg site, Mg is bonded to six O atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Mg–O bond distances ranging from 2.06–2.30 Å. B is bonded in a single-bond geometry to five O atoms. There is one shorter (1.37 Å) and four longer (2.22 Å) B–O bond length. There are eleven inequivalent O sites. In the first O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with two equivalent OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with twelve OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to five Mg atoms to form a mixture of corner and edge-sharing OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 9–82°. In the third O site, O is bonded to one Rb and five Mg atoms to form a mixture of distorted corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedral tilt angles are 5°. In the fourth O site, O is bonded to six Mg atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the fifth O site, O is bonded in a distorted single-bond geometry to five Mg and one B atom. In the sixth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 0–11°. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with eleven ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the eighth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with six OMg5B octahedra and edges with eleven OMg6 octahedra. The corner-sharing octahedra tilt angles range from 2–23°. In the ninth O site, O is bonded to five Mg and one B atom to form distorted OMg5B octahedra that share corners with six OMg5B octahedra, a cornercorner with one OMg5 square pyramid, and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–23°. In the tenth O site, O is bonded to six Mg atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg5B octahedra, edges with ten OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–7°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO31 by Materials Project

RbMg30BO31 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded to six O atoms to form RbO6 octahedra that share corners with four MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Rb–O bond distances ranging from 2.38–2.47 Å. There are sixteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a T-shaped geometry to three O atoms. There are two shorter (1.88 Å) and one longer (2.15 Å) Mg–O bond lengths. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent RbO6 octahedra, corners with two equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Mg–O bond distances ranging from 1.91–2.28 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent RbO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.91–2.25 Å. In the fourth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are a spread of Mg–O bond distances ranging from 2.10–2.16 Å. In the fifth Mg site, Mg is bonded to six O atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.07–2.20 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mg–O bond distances ranging from 1.98–2.23 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one RbO6 octahedra, edges with seven MgO6 octahedra, and edges with two MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 4–33°. There are a spread of Mg–O bond distances ranging from 2.02–2.31 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with nine MgO6 octahedra, and edges with three MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.14–2.19 Å. In the ninth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, an edgeedge with one RbO6 octahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–15°. There are a spread of Mg–O bond distances ranging from 2.15–2.19 Å. In the tenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 4–14°. There are a spread of Mg–O bond distances ranging from 2.13–2.25 Å. In the eleventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, an edgeedge with one RbO6 octahedra, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Mg–O bond distances ranging from 2.14–2.20 Å. In the twelfth Mg site, Mg is bonded to six O atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 4–5°. There are a spread of Mg–O bond distances ranging from 2.06–2.30 Å. In the thirteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, an edgeedge with one RbO6 octahedra, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Mg–O bond distances ranging from 2.11–2.20 Å. In the fourteenth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 3–35°. There are a spread of Mg–O bond distances ranging from 1.99–2.39 Å. In the fifteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one RbO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. There are a spread of Mg–O bond distances ranging from 2.14–2.21 Å. In the sixteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Mg–O bond distances ranging from 2.07–2.24 Å. B is bonded in a distorted trigonal planar geometry to three O atoms. There is two shorter (1.45 Å) and one longer (1.47 Å) B–O bond length. There are seventeen inequivalent O sites. In the first O site, O is bonded to one Rb and five Mg atoms to form a mixture of corner and edge-sharing ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the second O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four ORbMg5 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–7°. In the third O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with three OMg5B octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the fourth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with six ORbMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the fifth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four ORbMg5 octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 5–6°. In the sixth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–8°. In the seventh O site, O is bonded to five Mg and one B atom to form distorted OMg5B octahedra that share corners with four OMg6 octahedra, corners with three OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with eight ORbMg5 octahedra, and edges with two OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–8°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–7°. In the tenth O site, O is bonded to one Rb and five Mg atoms to form distorted ORbMg5 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with nine ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the eleventh O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with five OMg5B octahedra, corners with two OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 4–93°. In the twelfth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with eleven ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the thirteenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with eleven OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–4°. In the fourteenth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg6 octahedra, edges with ten ORbMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–7°. In the fifteenth O site, O is bonded in a distorted single-bond geometry to four Mg and one B atom. In the sixteenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve ORbMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the seventeenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–2°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg6BO8 by Materials Project

RbMg6BO8 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Rb1+ is bonded to six O2- atoms to form RbO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four equivalent RbO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.31 Å) and two longer (2.42 Å) Rb–O bond lengths. There are three 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 RbO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.89 Å) and four longer (2.31 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Mg–O bond lengths are 2.31 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent RbO6 octahedra, and edges with six MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–28°. There are a spread of Mg–O bond distances ranging from 2.01–2.38 Å. B3+ is bonded in a linear geometry to six O2- atoms. There is two shorter (1.42 Å) and four longer (2.31 Å) B–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to one Rb1+ and five Mg2+ atoms to form distorted ORbMg5 octahedra that share corners with six equivalent ORbMg5 octahedra and edges with eight ORb2Mg2B2 octahedra. The corner-sharing octahedra tilt angles range from 0–20°. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent Mg2+ and one B3+ atom. In the third O2- site, O2- is bonded to two equivalent Rb1+, two equivalent Mg2+, and two equivalent B3+ atoms to form distorted ORb2Mg2B2 octahedra that share corners with six ORb2Mg2B2 octahedra and edges with eight ORbMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six ORb2Mg2B2 octahedra and edges with eight ORbMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O2- site, O2- is bonded to two equivalent Rb1+, two equivalent Mg2+, and two equivalent B3+ atoms to form distorted ORb2Mg2B2 octahedra that share corners with six OMg6 octahedra and edges with eight ORbMg5 octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.01 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO31 by Materials Project

RbMg30BO31 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded in a 3-coordinate geometry to three O atoms. There are two shorter (2.45 Å) and one longer (2.50 Å) Rb–O bond lengths. There are sixteen inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.98–2.21 Å. In the second Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.00–2.22 Å. In the third Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.04–2.28 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mg–O bond distances ranging from 1.97–2.22 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.09–2.14 Å. In the sixth Mg site, Mg is bonded to six O 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 2.09–2.21 Å. In the seventh Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with six MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 3–33°. There are a spread of Mg–O bond distances ranging from 2.04–2.44 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with nine MgO6 octahedra, and edges with three MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Mg–O bond distances ranging from 2.10–2.21 Å. In the ninth Mg site, Mg is bonded to five O atoms to form distorted MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–35°. There are a spread of Mg–O bond distances ranging from 1.96–2.42 Å. In the tenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.08–2.23 Å. In the eleventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Mg–O bond distances ranging from 2.03–2.26 Å. In the twelfth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Mg–O bond distances ranging from 2.09–2.23 Å. In the thirteenth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Mg–O bond distances ranging from 2.09–2.19 Å. In the fourteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 2–15°. There are a spread of Mg–O bond distances ranging from 2.09–2.27 Å. In the fifteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Mg–O bond distances ranging from 2.10–2.25 Å. In the sixteenth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Mg–O bond distances ranging from 2.09–2.33 Å. B is bonded in a distorted trigonal planar geometry to three O atoms. There is two shorter (1.43 Å) and one longer (1.46 Å) B–O bond length. There are seventeen inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with three OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the second O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the third O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg5B octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fifth O site, O is bonded to five Mg and one B atom to form distorted OMg5B octahedra that share corners with four ORbMg5 octahedra, corners with three OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the sixth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with eight OMg6 octahedra, and edges with two OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–10°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–8°. In the tenth O site, O is bonded in a distorted single-bond geometry to four Mg and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 1°. In the twelfth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 0–7°. In the thirteenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. In the fourteenth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with nine OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the fifteenth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with five OMg5B octahedra, corners with two OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–90°. In the sixteenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the seventeenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with eleven OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 0–4°.

36 MATERIALS SCIENCE↗