DOI: 10.17188/1676984
title: Materials Data on NaMg14BO15 by Materials Project

description: NaMg14BO15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Na is bonded to five O atoms to form NaO5 square pyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent NaO5 square pyramids, 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 Na–O bond distances ranging from 2.17–2.41 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 NaO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of Mg–O bond distances ranging from 1.97–2.27 Å. In the second Mg site, Mg is bonded in a T-shaped geometry to three O atoms. There are one shorter (2.00 Å) and two longer (2.17 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 six MgO6 octahedra, edges with seven MgO6 octahedra, edges with two equivalent NaO5 square pyramids, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 2–7°. There are a spread of Mg–O bond distances ranging from 2.10–2.18 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 five MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–29°. There are a spread of Mg–O bond distances ranging from 1.98–2.27 Å. In the fifth Mg site, Mg is bonded in a square co-planar geometry to four O atoms. There are a spread of Mg–O bond distances ranging from 2.10–2.15 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with six MgO6 octahedra, and edges with four equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–11°. There are a spread of Mg–O bond distances ranging from 2.10–2.26 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 NaO5 square pyramids. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Mg–O bond distances ranging from 2.11–2.18 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 0–8°. There are a spread of Mg–O bond distances ranging from 2.04–2.18 Å. In the ninth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with two equivalent MgO6 octahedra, a cornercorner with one NaO5 square pyramid, corners with three equivalent MgO5 square pyramids, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 3–33°. There are a spread of Mg–O bond distances ranging from 1.96–2.31 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, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and an edgeedge with one NaO5 square pyramid. The corner-sharing octahedra tilt angles range from 5–16°. There are a spread of Mg–O bond distances ranging from 2.04–2.25 Å. B is bonded in a 3-coordinate geometry to five O atoms. There are a spread of B–O bond distances ranging from 1.48–2.21 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 OMg5B octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O site, O is bonded to one Na and five Mg atoms to form ONaMg5 octahedra that share corners with four ONaMg5 octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedral tilt angles are 13°. 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 ONaMg5 octahedra, a cornercorner with one OMg5 square pyramid, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 8–13°. 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 five ONa2Mg4 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–9°. 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 nine ONaMg5 octahedra. The corner-sharing octahedra tilt angles range from 2–7°. In the sixth O site, O is bonded to two equivalent Na and four Mg atoms to form a mixture of edge and corner-sharing ONa2Mg4 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the seventh 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 square pyramids. The corner-sharing octahedra tilt angles range from 1–4°. 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 six ONaMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the ninth O site, O is bonded in a distorted square co-planar geometry to four Mg and two equivalent B atoms. In the tenth O site, O is bonded to one Na and five Mg atoms to form ONaMg5 octahedra that share corners with four equivalent ONaMg5 octahedra, edges with ten ONaMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 2–7°. In the eleventh O site, O is bonded in a 1-coordinate geometry to four Mg and one B atom.