Materials Data on Mg6CuSi by Materials Project

Mg6CuSi crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to eight Mg, two equivalent Cu, and two equivalent Si atoms to form distorted MgMg8Cu2Si2 cuboctahedra that share corners with two equivalent CuMg10 cuboctahedra, corners with two equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent SiMg10 cuboctahedra, edges with three equivalent CuMg10 cuboctahedra, edges with twelve MgMg8Cu2Si2 cuboctahedra, a faceface with one CuMg10 cuboctahedra, faces with two equivalent SiMg10 cuboctahedra, and faces with sixteen MgMg8Cu2Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.96–3.10 Å. There are one shorter (3.01 Å) and one longer (3.05 Å) Mg–Cu bond lengths. Both Mg–Si bond lengths are 3.01 Å. In the second Mg site, Mg is bonded to eight Mg, two equivalent Cu, and two equivalent Si atoms to form distorted MgMg8Cu2Si2 cuboctahedra that share corners with two equivalent CuMg10 cuboctahedra, corners with two equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent SiMg10 cuboctahedra, edges with three equivalent CuMg10 cuboctahedra, edges with twelve MgMg10Cu2 cuboctahedra, a faceface with one CuMg10 cuboctahedra, faces with two equivalent SiMg10 cuboctahedra, and faces with sixteen MgMg8Cu2Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.01–3.10 Å. There are one shorter (3.01 Å) and one longer (3.05 Å) Mg–Cu bond lengths. Both Mg–Si bond lengths are 3.01 Å. In the third Mg site, Mg is bonded to ten Mg and two equivalent Cu atoms to form distorted MgMg10Cu2 cuboctahedra that share corners with four equivalent CuMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent CuMg10 cuboctahedra, edges with sixteen MgMg8Cu2Si2 cuboctahedra, faces with two equivalent CuMg10 cuboctahedra, faces with six equivalent SiMg10 cuboctahedra, and faces with twelve MgMg8Cu2Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.01–3.04 Å. Both Mg–Cu bond lengths are 3.01 Å. In the fourth Mg site, Mg is bonded to eight Mg, two equivalent Cu, and two equivalent Si atoms to form distorted MgMg8Cu2Si2 cuboctahedra that share corners with two equivalent CuMg10 cuboctahedra, corners with two equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent CuMg10 cuboctahedra, edges with three equivalent SiMg10 cuboctahedra, edges with twelve MgMg10Cu2 cuboctahedra, a faceface with one SiMg10 cuboctahedra, faces with two equivalent CuMg10 cuboctahedra, and faces with sixteen MgMg8Cu2Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.90–3.13 Å. Both Mg–Cu bond lengths are 2.97 Å. There are one shorter (2.94 Å) and one longer (3.12 Å) Mg–Si bond lengths. In the fifth Mg site, Mg is bonded to eight Mg, two equivalent Cu, and two equivalent Si atoms to form distorted MgMg8Cu2Si2 cuboctahedra that share corners with two equivalent CuMg10 cuboctahedra, corners with two equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent CuMg10 cuboctahedra, edges with three equivalent SiMg10 cuboctahedra, edges with twelve MgMg8Cu2Si2 cuboctahedra, a faceface with one SiMg10 cuboctahedra, faces with two equivalent CuMg10 cuboctahedra, and faces with sixteen MgMg8Cu2Si2 cuboctahedra. There are one shorter (3.00 Å) and one longer (3.06 Å) Mg–Mg bond lengths. Both Mg–Cu bond lengths are 2.97 Å. There are one shorter (2.94 Å) and one longer (3.12 Å) Mg–Si bond lengths. In the sixth Mg site, Mg is bonded to ten Mg and two equivalent Si atoms to form distorted MgMg10Si2 cuboctahedra that share corners with four equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent SiMg10 cuboctahedra, edges with sixteen MgMg8Cu2Si2 cuboctahedra, faces with two equivalent SiMg10 cuboctahedra, faces with six equivalent CuMg10 cuboctahedra, and faces with twelve MgMg8Cu2Si2 cuboctahedra. Both Mg–Si bond lengths are 3.01 Å. In the seventh Mg site, Mg is bonded to eight Mg, two equivalent Cu, and two equivalent Si atoms to form distorted MgMg8Cu2Si2 cuboctahedra that share corners with two equivalent CuMg10 cuboctahedra, corners with two equivalent SiMg10 cuboctahedra, corners with fourteen MgMg8Cu2Si2 cuboctahedra, edges with two equivalent SiMg10 cuboctahedra, edges with three equivalent CuMg10 cuboctahedra, edges with twelve MgMg8Cu2Si2 cuboctahedra, a faceface with one CuMg10 cuboctahedra, faces with two equivalent SiMg10 cuboctahedra, and faces with sixteen MgMg8Cu2Si2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.96–3.10 Å. There are one shorter (3.01 Å) and one longer (3.05 Å) Mg–Cu bond lengths. Both Mg–Si bond lengths are 3.01 Å. Cu is bonded to ten Mg atoms to form distorted CuMg10 cuboctahedra that share corners with six equivalent CuMg10 cuboctahedra, corners with twelve MgMg8Cu2Si2 cuboctahedra, edges with two equivalent CuMg10 cuboctahedra, edges with four equivalent SiMg10 cuboctahedra, edges with twelve MgMg8Cu2Si2 cuboctahedra, faces with two equivalent SiMg10 cuboctahedra, and faces with fourteen MgMg8Cu2Si2 cuboctahedra. Si is bonded to ten Mg atoms to form distorted SiMg10 cuboctahedra that share corners with six equivalent SiMg10 cuboctahedra, corners with twelve MgMg8Cu2Si2 cuboctahedra, edges with two equivalent SiMg10 cuboctahedra, edges with four equivalent CuMg10 cuboctahedra, edges with twelve MgMg8Cu2Si2 cuboctahedra, faces with two equivalent CuMg10 cuboctahedra, and faces with fourteen MgMg8Cu2Si2 cuboctahedra.