DOI: 10.17188/1689021
title: Materials Data on Mg149Pb by Materials Project

description: Mg149Pb is alpha Samarium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. there are twenty-seven inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted single-bond geometry to seven Mg and one Pb atom. There are a spread of Mg–Mg bond distances ranging from 3.16–3.18 Å. The Mg–Pb bond length is 3.23 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with sixteen MgMg12 cuboctahedra, an edgeedge with one PbMg12 cuboctahedra, edges with thirteen MgMg12 cuboctahedra, and faces with eighteen MgMg12 cuboctahedra. There are eight shorter (3.18 Å) and two longer (3.20 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.18 Å. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with sixteen MgMg12 cuboctahedra, an edgeedge with one PbMg12 cuboctahedra, edges with seventeen MgMg12 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are six shorter (3.18 Å) and four longer (3.19 Å) Mg–Mg bond lengths. In the fifth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share a cornercorner with one PbMg12 cuboctahedra, corners with sixteen MgMg12 cuboctahedra, edges with fourteen MgMg12 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.18 Å. In the sixth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are six shorter (3.18 Å) and two longer (3.19 Å) Mg–Mg bond lengths. In the seventh Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are five shorter (3.18 Å) and four longer (3.19 Å) Mg–Mg bond lengths. In the eighth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.18 Å. In the ninth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with sixteen MgMg12 cuboctahedra, an edgeedge with one PbMg12 cuboctahedra, edges with fifteen MgMg12 cuboctahedra, and faces with seventeen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.19 Å. In the tenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.18 Å) and four longer (3.19 Å) Mg–Mg bond lengths. In the eleventh Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.18 Å. In the twelfth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with sixteen MgMg12 cuboctahedra, edges with fifteen MgMg12 cuboctahedra, a faceface with one PbMg12 cuboctahedra, and faces with fifteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.19 Å. In the thirteenth Mg site, Mg is bonded in a distorted single-bond geometry to seven Mg and one Pb atom. There are two shorter (3.15 Å) and one longer (3.17 Å) Mg–Mg bond lengths. The Mg–Pb bond length is 3.23 Å. In the fourteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.18 Å) and six longer (3.19 Å) Mg–Mg bond lengths. In the fifteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.18 Å) and six longer (3.19 Å) Mg–Mg bond lengths. In the sixteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are five shorter (3.18 Å) and two longer (3.19 Å) Mg–Mg bond lengths. In the seventeenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.18 Å) and three longer (3.19 Å) Mg–Mg bond lengths. In the eighteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.18 Å) and two longer (3.19 Å) Mg–Mg bond lengths. In the nineteenth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with twelve MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one PbMg12 cuboctahedra, and faces with sixteen MgMg12 cuboctahedra. There are three shorter (3.17 Å) and six longer (3.19 Å) Mg–Mg bond lengths. In the twentieth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share a cornercorner with one PbMg12 cuboctahedra, corners with fifteen MgMg12 cuboctahedra, edges with seventeen MgMg12 cuboctahedra, and faces with seventeen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.19 Å. In the twenty-first Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.19 Å. In the twenty-second Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are one shorter (3.18 Å) and five longer (3.19 Å) Mg–Mg bond lengths. In the twenty-third Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.19 Å. In the twenty-fourth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. In the twenty-fifth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.19 Å. In the twenty-sixth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.19 Å. In the twenty-seventh Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.19 Å. Pb is bonded to twelve Mg atoms to form PbMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with eight MgMg12 cuboctahedra.