DOI: 10.17188/1674292
title: Materials Data on SrCaMg14 by Materials Project

description: SrCaMg14 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Sr is bonded to two equivalent Ca and ten Mg atoms to form SrCa2Mg10 cuboctahedra that share corners with six equivalent SrCa2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with sixteen MgSr2Ca2Mg8 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. Both Sr–Ca bond lengths are 3.34 Å. There are a spread of Sr–Mg bond distances ranging from 3.31–3.43 Å. Ca is bonded to two equivalent Sr and ten Mg atoms to form CaSr2Mg10 cuboctahedra that share corners with six equivalent CaSr2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with sixteen MgSr2Ca2Mg8 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Ca–Mg bond distances ranging from 3.27–3.41 Å. There are eleven 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 SrCa2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.35 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent CaSr2Mg10 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.19–3.34 Å. In the third Mg site, Mg is bonded to two equivalent Sr, two equivalent Ca, and eight Mg atoms to form distorted MgSr2Ca2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgSr2Ca2Mg8 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.32–3.38 Å. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent SrCa2Mg10 cuboctahedra, corners with four equivalent CaSr2Mg10 cuboctahedra, corners with ten MgSr2Ca2Mg8 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.14–3.36 Å. In the fifth Mg site, Mg is bonded to two equivalent Sr, two equivalent Ca, and eight Mg atoms to form distorted MgSr2Ca2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgSr2Ca2Mg8 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.32–3.38 Å. In the sixth Mg site, Mg is bonded to one Sr, one Ca, and ten Mg atoms to form distorted MgSrCaMg10 cuboctahedra that share corners with eighteen MgSrMg11 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, a faceface with one SrCa2Mg10 cuboctahedra, a faceface with one CaSr2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.24–3.43 Å. In the seventh Mg site, Mg is bonded to one Sr, one Ca, and ten Mg atoms to form distorted MgSrCaMg10 cuboctahedra that share corners with eighteen MgSrMg11 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, a faceface with one SrCa2Mg10 cuboctahedra, a faceface with one CaSr2Mg10 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.14–3.43 Å. In the eighth Mg site, Mg is bonded to one Ca and eleven Mg atoms to form distorted MgCaMg11 cuboctahedra that share corners with eighteen MgSrMg11 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with sixteen MgMg12 cuboctahedra, a faceface with one CaSr2Mg10 cuboctahedra, faces with three equivalent SrCa2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are one shorter (3.32 Å) and two longer (3.34 Å) Mg–Mg bond lengths. In the ninth Mg site, Mg is bonded to one Sr and eleven Mg atoms to form distorted MgSrMg11 cuboctahedra that share corners with eighteen MgSrMg11 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with sixteen MgMg12 cuboctahedra, a faceface with one SrCa2Mg10 cuboctahedra, faces with three equivalent CaSr2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. The Mg–Mg bond length is 3.34 Å. In the tenth Mg site, Mg is bonded to two equivalent Sr, two equivalent Ca, and eight Mg atoms to form distorted MgSr2Ca2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgSrCaMg10 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.32–3.38 Å. In the eleventh Mg site, Mg is bonded to two equivalent Sr, two equivalent Ca, and eight Mg atoms to form distorted MgSr2Ca2Mg8 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent SrCa2Mg10 cuboctahedra, edges with two equivalent CaSr2Mg10 cuboctahedra, edges with fourteen MgSrCaMg10 cuboctahedra, faces with two equivalent SrCa2Mg10 cuboctahedra, faces with two equivalent CaSr2Mg10 cuboctahedra, and faces with sixteen MgSr2Ca2Mg8 cuboctahedra. Both Mg–Mg bond lengths are 3.38 Å.