Materials Data on Mg6CuNi by Materials Project
Mg6NiCu crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to eight Mg, two equivalent Ni, and two equivalent Cu atoms. There are a spread of Mg–Mg bond distances ranging from 2.78–3.11 Å. Both Mg–Ni bond lengths are 2.86 Å. There are one shorter (2.82 Å) and one longer (3.09 Å) Mg–Cu bond lengths. In the second Mg site, Mg is bonded to ten Mg and two equivalent Cu atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent CuMg10Ni2 cuboctahedra, corners with six equivalent MgMg10Cu2 cuboctahedra, edges with two equivalent CuMg10Ni2 cuboctahedra, edges with twelve MgMg8Cu2Ni2 cuboctahedra, faces with two equivalent CuMg10Ni2 cuboctahedra, faces with six equivalent NiMg10Cu2 cuboctahedra, and faces with eight MgMg10Cu2 cuboctahedra. There are four shorter (2.94 Å) and two longer (2.96 Å) Mg–Mg bond lengths. Both Mg–Cu bond lengths are 2.95 Å. In the third Mg site, Mg is bonded to eight Mg, two equivalent Ni, and two equivalent Cu atoms to form distorted MgMg8Cu2Ni2 cuboctahedra that share corners with four equivalent NiMg10Cu2 cuboctahedra, corners with fourteen MgMg8Cu2Ni2 cuboctahedra, edges with two equivalent NiMg10Cu2 cuboctahedra, edges with four equivalent CuMg10Ni2 cuboctahedra, edges with eight MgMg10Cu2 cuboctahedra, faces with two equivalent NiMg10Cu2 cuboctahedra, faces with two equivalent CuMg10Ni2 cuboctahedra, and faces with eight MgMg10Cu2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.82–3.07 Å. There are one shorter (2.89 Å) and one longer (3.03 Å) Mg–Ni bond lengths. Both Mg–Cu bond lengths are 2.89 Å. In the fourth Mg site, Mg is bonded to ten Mg and two equivalent Ni atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent NiMg10Cu2 cuboctahedra, corners with fourteen MgMg8Cu2Ni2 cuboctahedra, edges with two equivalent NiMg10Cu2 cuboctahedra, edges with eight MgMg10Cu2 cuboctahedra, faces with two equivalent NiMg10Cu2 cuboctahedra, faces with six equivalent CuMg10Ni2 cuboctahedra, and faces with eight MgMg10Cu2 cuboctahedra. Both Mg–Ni bond lengths are 2.95 Å. Ni is bonded to ten Mg and two equivalent Cu atoms to form distorted NiMg10Cu2 cuboctahedra that share corners with six equivalent NiMg10Cu2 cuboctahedra, corners with twelve MgMg8Cu2Ni2 cuboctahedra, edges with four equivalent CuMg10Ni2 cuboctahedra, edges with six MgMg8Cu2Ni2 cuboctahedra, faces with two equivalent NiMg10Cu2 cuboctahedra, faces with two equivalent CuMg10Ni2 cuboctahedra, and faces with twelve MgMg10Cu2 cuboctahedra. Both Ni–Cu bond lengths are 2.96 Å. Cu is bonded to ten Mg and two equivalent Ni atoms to form distorted CuMg10Ni2 cuboctahedra that share corners with four equivalent MgMg10Cu2 cuboctahedra, corners with six equivalent CuMg10Ni2 cuboctahedra, edges with four equivalent NiMg10Cu2 cuboctahedra, edges with ten MgMg10Cu2 cuboctahedra, faces with two equivalent NiMg10Cu2 cuboctahedra, faces with two equivalent CuMg10Ni2 cuboctahedra, and faces with twelve MgMg10Cu2 cuboctahedra.