DOE OSTI2020
Mn7Pd9 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are three inequivalent Mn sites. In the first Mn site, Mn is bonded to four equivalent Mn and eight equivalent Pd atoms to form distorted MnMn4Pd8 cuboctahedra that share corners with four equivalent PdMn4Pd8 cuboctahedra, corners with eight MnMn4Pd8 cuboctahedra, edges with eight equivalent MnMn3Pd9 cuboctahedra, edges with sixteen equivalent PdMn7Pd5 cuboctahedra, faces with eight MnMn4Pd8 cuboctahedra, and faces with ten PdMn7Pd5 cuboctahedra. All Mn–Mn bond lengths are 2.66 Å. There are four shorter (2.63 Å) and four longer (2.70 Å) Mn–Pd bond lengths. In the second Mn site, Mn is bonded to four equivalent Mn and eight equivalent Pd atoms to form distorted MnMn4Pd8 cuboctahedra that share corners with four equivalent PdMn4Pd8 cuboctahedra, corners with eight equivalent MnMn4Pd8 cuboctahedra, edges with eight equivalent MnMn3Pd9 cuboctahedra, edges with sixteen equivalent PdMn7Pd5 cuboctahedra, faces with eight MnMn4Pd8 cuboctahedra, and faces with ten PdMn7Pd5 cuboctahedra. All Mn–Mn bond lengths are 2.60 Å. All Mn–Pd bond lengths are 2.66 Å. In the third Mn site, Mn is bonded to three Mn and nine Pd atoms to form distorted MnMn3Pd9 cuboctahedra that share corners with twelve equivalent MnMn3Pd9 cuboctahedra, edges with six MnMn4Pd8 cuboctahedra, edges with eighteen PdMn7Pd5 cuboctahedra, faces with nine MnMn4Pd8 cuboctahedra, and faces with nine PdMn7Pd5 cuboctahedra. There are a spread of Mn–Pd bond distances ranging from 2.62–2.75 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to seven Mn and five Pd atoms to form distorted PdMn7Pd5 cuboctahedra that share corners with twelve equivalent PdMn7Pd5 cuboctahedra, edges with ten PdMn7Pd5 cuboctahedra, edges with fourteen MnMn4Pd8 cuboctahedra, faces with seven MnMn4Pd8 cuboctahedra, and faces with eleven PdMn7Pd5 cuboctahedra. There are a spread of Pd–Pd bond distances ranging from 2.63–2.73 Å. In the second Pd site, Pd is bonded to four equivalent Mn and eight equivalent Pd atoms to form distorted PdMn4Pd8 cuboctahedra that share corners with twelve MnMn4Pd8 cuboctahedra, edges with eight equivalent MnMn3Pd9 cuboctahedra, edges with sixteen equivalent PdMn7Pd5 cuboctahedra, faces with eight equivalent PdMn7Pd5 cuboctahedra, and faces with ten MnMn4Pd8 cuboctahedra.