DOE OSTI2019
Mg149Pr is Magnesium-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 to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgPrMg11 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, an edgeedge with one PrMg12 cuboctahedra, edges with seventeen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.22 Å. In the third Mg site, Mg is bonded to eleven Mg and one Pr atom to form distorted MgPrMg11 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one PrMg12 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.12–3.36 Å. The Mg–Pr bond length is 3.28 Å. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share a cornercorner with one PrMg12 cuboctahedra, corners with seventeen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the fifth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, an edgeedge with one PrMg12 cuboctahedra, edges with seventeen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.15–3.21 Å. In the sixth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the seventh Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one PrMg12 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.15–3.24 Å. In the eighth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are three shorter (3.19 Å) and six longer (3.21 Å) Mg–Mg bond lengths. In the ninth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.23 Å. In the tenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.16–3.19 Å. In the eleventh Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.20 Å. In the twelfth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, an edgeedge with one PrMg12 cuboctahedra, edges with seventeen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.20 Å. In the thirteenth Mg site, Mg is bonded to eleven Mg and one Pr atom to form MgPrMg11 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one PrMg12 cuboctahedra, and faces with nineteen MgPrMg11 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.13–3.29 Å. The Mg–Pr bond length is 3.28 Å. In the fourteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the fifteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are six shorter (3.19 Å) and one longer (3.20 Å) Mg–Mg bond lengths. In the sixteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the seventeenth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share a cornercorner with one PrMg12 cuboctahedra, corners with seventeen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgPrMg11 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.21 Å. In the eighteenth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.20 Å. In the nineteenth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgPrMg11 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.18 Å. In the twentieth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one PrMg12 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.18 Å. In the twenty-first Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are two shorter (3.19 Å) and four longer (3.20 Å) Mg–Mg bond lengths. In the twenty-second Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.20 Å. In the twenty-third Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.21 Å. In the twenty-fourth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. In the twenty-fifth Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, 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 face, edge, and corner-sharing MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.20 Å. In the twenty-seventh Mg site, Mg is bonded to twelve Mg atoms to form a mixture of face, edge, and corner-sharing MgMg12 cuboctahedra. Both Mg–Mg bond lengths are 3.19 Å. Pr is bonded to twelve Mg atoms to form PrMg12 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgMg12 cuboctahedra.