DOI: 10.17188/1748995
title: Materials Data on Mg4Sc by Materials Project

description: Mg4Sc is alpha La-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to nine Mg and three equivalent Sc atoms to form MgMg9Sc3 cuboctahedra that share corners with twelve MgMg9Sc3 cuboctahedra, edges with six equivalent ScMg6Sc6 cuboctahedra, edges with eighteen MgMg9Sc3 cuboctahedra, faces with six equivalent ScMg6Sc6 cuboctahedra, and faces with twelve MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and three longer (3.22 Å) Mg–Mg bond lengths. All Mg–Sc bond lengths are 3.23 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and three longer (3.22 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and three longer (3.22 Å) Mg–Mg bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and six longer (3.22 Å) Mg–Mg bond lengths. In the fifth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and three longer (3.22 Å) Mg–Mg bond lengths. In the sixth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and six longer (3.22 Å) Mg–Mg bond lengths. In the seventh Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with three equivalent ScMg6Sc6 cuboctahedra, corners with nine MgMg9Sc3 cuboctahedra, edges with three equivalent ScMg6Sc6 cuboctahedra, edges with twenty-one MgMg9Sc3 cuboctahedra, and faces with eighteen MgMg9Sc3 cuboctahedra. There are six shorter (3.20 Å) and three longer (3.22 Å) Mg–Mg bond lengths. Sc is bonded to six equivalent Mg and six equivalent Sc atoms to form ScMg6Sc6 cuboctahedra that share corners with six MgMg12 cuboctahedra, corners with six equivalent ScMg6Sc6 cuboctahedra, edges with six equivalent ScMg6Sc6 cuboctahedra, edges with eighteen MgMg9Sc3 cuboctahedra, faces with six equivalent ScMg6Sc6 cuboctahedra, and faces with twelve equivalent MgMg9Sc3 cuboctahedra. All Sc–Sc bond lengths are 3.20 Å.