DOI: 10.17188/1653582
title: Materials Data on BaCaMg14 by Materials Project

description: BaCaMg14 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Ba is bonded to two equivalent Ca and ten Mg atoms to form BaCa2Mg10 cuboctahedra that share corners with six equivalent BaCa2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent CaBa2Mg10 cuboctahedra, edges with twelve MgBaCaMg10 cuboctahedra, faces with two equivalent CaBa2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. Both Ba–Ca bond lengths are 3.34 Å. There are a spread of Ba–Mg bond distances ranging from 3.36–3.50 Å. Ca is bonded to two equivalent Ba and ten Mg atoms to form CaBa2Mg10 cuboctahedra that share corners with six equivalent CaBa2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent BaCa2Mg10 cuboctahedra, edges with sixteen MgBaCaMg10 cuboctahedra, faces with two equivalent BaCa2Mg10 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. There are a spread of Ca–Mg bond distances ranging from 3.30–3.45 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent BaCa2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with eighteen MgBaCaMg10 cuboctahedra, faces with two equivalent CaBa2Mg10 cuboctahedra, and faces with twelve MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.39 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent CaBa2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with fourteen MgBaCaMg10 cuboctahedra, faces with two equivalent BaCa2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.19–3.38 Å. In the third Mg site, Mg is bonded to two equivalent Ba, two equivalent Ca, and eight Mg atoms to form distorted MgBa2Ca2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent BaCa2Mg10 cuboctahedra, edges with two equivalent CaBa2Mg10 cuboctahedra, edges with ten MgBa2Ca2Mg8 cuboctahedra, faces with two equivalent BaCa2Mg10 cuboctahedra, faces with two equivalent CaBa2Mg10 cuboctahedra, and faces with fourteen MgBa2Ca2Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.31–3.44 Å. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent BaCa2Mg10 cuboctahedra, corners with four equivalent CaBa2Mg10 cuboctahedra, corners with ten MgBa2Ca2Mg8 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.14–3.35 Å. In the fifth Mg site, Mg is bonded to one Ba, one Ca, and ten Mg atoms to form distorted MgBaCaMg10 cuboctahedra that share corners with fourteen MgBaCaMg10 cuboctahedra, edges with two equivalent BaCa2Mg10 cuboctahedra, edges with two equivalent CaBa2Mg10 cuboctahedra, edges with twelve MgMg12 cuboctahedra, a faceface with one BaCa2Mg10 cuboctahedra, a faceface with one CaBa2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.23–3.50 Å. In the sixth Mg site, Mg is bonded to one Ca and eleven Mg atoms to form distorted MgCaMg11 cuboctahedra that share corners with fourteen MgBaCaMg10 cuboctahedra, edges with two equivalent CaBa2Mg10 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, a faceface with one CaBa2Mg10 cuboctahedra, faces with three equivalent BaCa2Mg10 cuboctahedra, and faces with fourteen MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.34 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to one Ba and eleven Mg atoms.