DOE OSTI2020
Mn4Ga crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Mn sites. In the first Mn site, Mn is bonded to nine Mn and three equivalent Ga atoms to form MnMn9Ga3 cuboctahedra that share corners with twelve MnMn9Ga3 cuboctahedra, edges with six equivalent GaMn6Ga6 cuboctahedra, edges with eighteen MnMn9Ga3 cuboctahedra, faces with six equivalent GaMn6Ga6 cuboctahedra, and faces with twelve MnMn9Ga3 cuboctahedra. There are three shorter (2.40 Å) and six longer (2.56 Å) Mn–Mn bond lengths. All Mn–Ga bond lengths are 2.62 Å. In the second Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are six shorter (2.56 Å) and three longer (2.58 Å) Mn–Mn bond lengths. In the third Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are three shorter (2.40 Å) and six longer (2.56 Å) Mn–Mn bond lengths. In the fourth Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.40–2.58 Å. In the fifth Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are three shorter (2.40 Å) and six longer (2.56 Å) Mn–Mn bond lengths. In the sixth Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.40–2.58 Å. In the seventh Mn site, Mn is bonded to twelve Mn atoms to form MnMn12 cuboctahedra that share corners with three equivalent GaMn6Ga6 cuboctahedra, corners with nine MnMn9Ga3 cuboctahedra, edges with three equivalent GaMn6Ga6 cuboctahedra, edges with twenty-one MnMn9Ga3 cuboctahedra, and faces with eighteen MnMn9Ga3 cuboctahedra. There are three shorter (2.40 Å) and six longer (2.56 Å) Mn–Mn bond lengths. Ga is bonded to six equivalent Mn and six equivalent Ga atoms to form GaMn6Ga6 cuboctahedra that share corners with six MnMn12 cuboctahedra, corners with six equivalent GaMn6Ga6 cuboctahedra, edges with six equivalent GaMn6Ga6 cuboctahedra, edges with eighteen MnMn9Ga3 cuboctahedra, faces with six equivalent GaMn6Ga6 cuboctahedra, and faces with twelve equivalent MnMn9Ga3 cuboctahedra. All Ga–Ga bond lengths are 2.56 Å.