Materials Data on NaMg14B by Materials Project

Abstract

NaMg14B crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to ten Mg and two equivalent B atoms to form NaMg10B2 cuboctahedra that share corners with six equivalent NaMg10B2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with four equivalent MgNaMg11 cuboctahedra, and faces with four MgMg12 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 3.07–3.19 Å. Both Na–B bond lengths are 3.16 Å. There are eight inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with six equivalent MgMg12 cuboctahedra, edges with ten MgMg12 cuboctahedra, faces with two equivalent NaMg10B2 cuboctahedra, and faces with eight MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.09–3.23 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent NaMg10B2 cuboctahedra, corners with six equivalent MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.14–3.22 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Na, eight Mg, and one B atom. There are a spread of Mg–Mg bond distances ranging from 3.04–3.27 Å. The Mg–B bond length is 3.09 Å. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent NaMg10B2 cuboctahedra, corners with six equivalent MgMg12 cuboctahedra, edges with ten MgMg12 cuboctahedra, and faces with eight MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.08–3.27 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to one Na, ten Mg, and one B atom. There are a spread of Mg–Mg bond distances ranging from 3.01–3.31 Å. The Mg–B bond length is 2.98 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to one Na, ten Mg, and one B atom. There are a spread of Mg–Mg bond distances ranging from 3.02–3.26 Å. The Mg–B bond length is 2.98 Å. In the seventh Mg site, Mg is bonded to one Na and eleven Mg atoms to form distorted MgNaMg11 cuboctahedra that share corners with six equivalent MgNaMg11 cuboctahedra, edges with two equivalent NaMg10B2 cuboctahedra, edges with six MgMg12 cuboctahedra, a faceface with one NaMg10B2 cuboctahedra, and faces with eight MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.17 Å. In the eighth Mg site, Mg is bonded in a 12-coordinate geometry to eleven Mg and one B atom. The Mg–B bond length is 2.98 Å. B is bonded in a 8-coordinate geometry to two equivalent Na and eight Mg atoms.