DOE OSTI2020
Mn3Ge is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are three inequivalent Mn sites. In the first Mn site, Mn is bonded to eight Mn and four equivalent Ge atoms to form distorted MnMn8Ge4 cuboctahedra that share corners with four equivalent GeMn12 cuboctahedra, corners with fourteen MnMn8Ge4 cuboctahedra, edges with six equivalent GeMn12 cuboctahedra, edges with twelve MnMn8Ge4 cuboctahedra, faces with four equivalent GeMn12 cuboctahedra, and faces with sixteen MnMn8Ge4 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.51–2.67 Å. There are two shorter (2.59 Å) and two longer (2.60 Å) Mn–Ge bond lengths. In the second Mn site, Mn is bonded to eight equivalent Mn and four equivalent Ge atoms to form distorted MnMn8Ge4 cuboctahedra that share corners with four equivalent GeMn12 cuboctahedra, corners with fourteen MnMn8Ge4 cuboctahedra, edges with six equivalent GeMn12 cuboctahedra, edges with twelve equivalent MnMn8Ge4 cuboctahedra, faces with four equivalent GeMn12 cuboctahedra, and faces with sixteen MnMn8Ge4 cuboctahedra. There are two shorter (2.59 Å) and two longer (2.60 Å) Mn–Ge bond lengths. In the third Mn site, Mn is bonded to eight equivalent Mn and four equivalent Ge atoms to form distorted MnMn8Ge4 cuboctahedra that share corners with four equivalent GeMn12 cuboctahedra, corners with fourteen MnMn8Ge4 cuboctahedra, edges with six equivalent GeMn12 cuboctahedra, edges with twelve equivalent MnMn8Ge4 cuboctahedra, faces with four equivalent GeMn12 cuboctahedra, and faces with sixteen MnMn8Ge4 cuboctahedra. There are two shorter (2.59 Å) and two longer (2.60 Å) Mn–Ge bond lengths. Ge is bonded to twelve Mn atoms to form GeMn12 cuboctahedra that share corners with six equivalent GeMn12 cuboctahedra, corners with twelve MnMn8Ge4 cuboctahedra, edges with eighteen MnMn8Ge4 cuboctahedra, faces with eight equivalent GeMn12 cuboctahedra, and faces with twelve MnMn8Ge4 cuboctahedra.