DOE OSTI2020
LiMg6Ga is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Li is bonded to ten Mg and two equivalent Ga atoms to form LiMg10Ga2 cuboctahedra that share corners with six equivalent LiMg10Ga2 cuboctahedra, corners with twelve MgLi2Mg8Ga2 cuboctahedra, edges with four equivalent GaLi2Mg10 cuboctahedra, edges with fourteen MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. There are a spread of Li–Mg bond distances ranging from 3.07–3.15 Å. Both Li–Ga bond lengths are 3.09 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Li, eight Mg, and two equivalent Ga atoms to form distorted MgLi2Mg8Ga2 cuboctahedra that share corners with four equivalent LiMg10Ga2 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent LiMg10Ga2 cuboctahedra, edges with four equivalent GaLi2Mg10 cuboctahedra, edges with twelve MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.06–3.16 Å. Both Mg–Ga bond lengths are 3.09 Å. In the second Mg site, Mg is bonded to two equivalent Li and ten Mg atoms to form MgLi2Mg10 cuboctahedra that share corners with four equivalent LiMg10Ga2 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent LiMg10Ga2 cuboctahedra, edges with sixteen MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with six equivalent GaLi2Mg10 cuboctahedra, and faces with twelve MgLi2Mg8Ga2 cuboctahedra. There are six shorter (3.10 Å) and one longer (3.12 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to two equivalent Li, eight Mg, and two equivalent Ga atoms to form distorted MgLi2Mg8Ga2 cuboctahedra that share corners with four equivalent GaLi2Mg10 cuboctahedra, corners with fourteen MgMg10Ga2 cuboctahedra, edges with two equivalent GaLi2Mg10 cuboctahedra, edges with four equivalent LiMg10Ga2 cuboctahedra, edges with twelve MgLi2Mg10 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.09–3.13 Å. There are one shorter (3.09 Å) and one longer (3.14 Å) Mg–Ga bond lengths. In the fourth Mg site, Mg is bonded to two equivalent Li, eight Mg, and two equivalent Ga atoms to form distorted MgLi2Mg8Ga2 cuboctahedra that share corners with four equivalent GaLi2Mg10 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent GaLi2Mg10 cuboctahedra, edges with four equivalent LiMg10Ga2 cuboctahedra, edges with twelve MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.10–3.13 Å. There are one shorter (3.09 Å) and one longer (3.14 Å) Mg–Ga bond lengths. In the fifth Mg site, Mg is bonded to ten Mg and two equivalent Ga atoms to form distorted MgMg10Ga2 cuboctahedra that share corners with four equivalent GaLi2Mg10 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent GaLi2Mg10 cuboctahedra, edges with sixteen MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, faces with six equivalent LiMg10Ga2 cuboctahedra, and faces with twelve MgLi2Mg8Ga2 cuboctahedra. The Mg–Mg bond length is 3.10 Å. Both Mg–Ga bond lengths are 3.11 Å. In the sixth Mg site, Mg is bonded to two equivalent Li, eight Mg, and two equivalent Ga atoms to form distorted MgLi2Mg8Ga2 cuboctahedra that share corners with four equivalent LiMg10Ga2 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent LiMg10Ga2 cuboctahedra, edges with four equivalent GaLi2Mg10 cuboctahedra, edges with twelve MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.06–3.16 Å. Both Mg–Ga bond lengths are 3.09 Å. In the seventh Mg site, Mg is bonded to two equivalent Li, eight Mg, and two equivalent Ga atoms to form distorted MgLi2Mg8Ga2 cuboctahedra that share corners with four equivalent GaLi2Mg10 cuboctahedra, corners with fourteen MgLi2Mg8Ga2 cuboctahedra, edges with two equivalent GaLi2Mg10 cuboctahedra, edges with four equivalent LiMg10Ga2 cuboctahedra, edges with twelve MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra. Both Mg–Li bond lengths are 3.10 Å. There are a spread of Mg–Mg bond distances ranging from 3.09–3.13 Å. There are one shorter (3.09 Å) and one longer (3.14 Å) Mg–Ga bond lengths. Ga is bonded to two equivalent Li and ten Mg atoms to form GaLi2Mg10 cuboctahedra that share corners with six equivalent GaLi2Mg10 cuboctahedra, corners with twelve MgLi2Mg8Ga2 cuboctahedra, edges with four equivalent LiMg10Ga2 cuboctahedra, edges with fourteen MgLi2Mg8Ga2 cuboctahedra, faces with two equivalent LiMg10Ga2 cuboctahedra, faces with two equivalent GaLi2Mg10 cuboctahedra, and faces with sixteen MgLi2Mg8Ga2 cuboctahedra.