Materials Data on Cu6SnGe by Materials Project
Cu6SnGe crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are four inequivalent Cu sites. In the first Cu site, Cu is bonded to eight Cu, two equivalent Sn, and two equivalent Ge atoms to form distorted CuCu8Sn2Ge2 cuboctahedra that share corners with four equivalent GeCu12 cuboctahedra, corners with fourteen CuCu8Sn2Ge2 cuboctahedra, edges with two equivalent GeCu12 cuboctahedra, edges with four equivalent SnCu12 cuboctahedra, edges with twelve CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent SnCu12 cuboctahedra, faces with two equivalent GeCu12 cuboctahedra, and faces with sixteen CuCu8Sn2Ge2 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.60–2.94 Å. Both Cu–Sn bond lengths are 2.71 Å. There are one shorter (2.63 Å) and one longer (2.69 Å) Cu–Ge bond lengths. In the second Cu site, Cu is bonded to eight Cu, two equivalent Sn, and two equivalent Ge atoms to form distorted CuCu8Sn2Ge2 cuboctahedra that share corners with four equivalent SnCu12 cuboctahedra, corners with fourteen CuCu8Sn2Ge2 cuboctahedra, edges with two equivalent SnCu12 cuboctahedra, edges with four equivalent GeCu12 cuboctahedra, edges with twelve CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent SnCu12 cuboctahedra, faces with two equivalent GeCu12 cuboctahedra, and faces with sixteen CuCu8Sn2Ge2 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.60–2.94 Å. There are one shorter (2.72 Å) and one longer (2.77 Å) Cu–Sn bond lengths. Both Cu–Ge bond lengths are 2.62 Å. In the third Cu site, Cu is bonded to eight Cu, two equivalent Sn, and two equivalent Ge atoms to form CuCu8Sn2Ge2 cuboctahedra that share corners with eight equivalent SnCu12 cuboctahedra, corners with ten CuCu8Sn2Ge2 cuboctahedra, edges with eighteen CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent SnCu12 cuboctahedra, faces with four equivalent GeCu12 cuboctahedra, and faces with fourteen CuCu8Sn2Ge2 cuboctahedra. Both Cu–Sn bond lengths are 2.77 Å. Both Cu–Ge bond lengths are 2.63 Å. In the fourth Cu site, Cu is bonded to eight Cu, two equivalent Sn, and two equivalent Ge atoms to form distorted CuCu8Sn2Ge2 cuboctahedra that share corners with eight equivalent GeCu12 cuboctahedra, corners with ten CuCu8Sn2Ge2 cuboctahedra, edges with eighteen CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent GeCu12 cuboctahedra, faces with four equivalent SnCu12 cuboctahedra, and faces with fourteen CuCu8Sn2Ge2 cuboctahedra. Both Cu–Sn bond lengths are 2.73 Å. Both Cu–Ge bond lengths are 2.77 Å. Sn is bonded to twelve Cu atoms to form SnCu12 cuboctahedra that share corners with two equivalent SnCu12 cuboctahedra, corners with sixteen CuCu8Sn2Ge2 cuboctahedra, edges with two equivalent SnCu12 cuboctahedra, edges with four equivalent GeCu12 cuboctahedra, edges with twelve CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent SnCu12 cuboctahedra, faces with four equivalent GeCu12 cuboctahedra, and faces with fourteen CuCu8Sn2Ge2 cuboctahedra. Ge is bonded to twelve Cu atoms to form GeCu12 cuboctahedra that share corners with two equivalent GeCu12 cuboctahedra, corners with sixteen CuCu8Sn2Ge2 cuboctahedra, edges with two equivalent GeCu12 cuboctahedra, edges with four equivalent SnCu12 cuboctahedra, edges with twelve CuCu8Sn2Ge2 cuboctahedra, faces with two equivalent GeCu12 cuboctahedra, faces with four equivalent SnCu12 cuboctahedra, and faces with fourteen CuCu8Sn2Ge2 cuboctahedra.