Materials Data on LiMg6Fe by Materials Project
LiMg6Fe 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 Fe atoms to form LiMg10Fe2 cuboctahedra that share corners with four equivalent MgLi2Mg10 cuboctahedra, corners with six equivalent LiMg10Fe2 cuboctahedra, edges with two equivalent MgLi2Mg10 cuboctahedra, edges with four equivalent FeLi2Mg10 cuboctahedra, faces with two equivalent LiMg10Fe2 cuboctahedra, faces with two equivalent FeLi2Mg10 cuboctahedra, and faces with eight MgMg10Fe2 cuboctahedra. There are a spread of Li–Mg bond distances ranging from 2.86–3.20 Å. Both Li–Fe bond lengths are 3.07 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Li, six Mg, and two equivalent Fe atoms. There are a spread of Mg–Mg bond distances ranging from 3.02–3.12 Å. There are one shorter (3.01 Å) and one longer (3.05 Å) Mg–Fe bond lengths. In the second Mg site, Mg is bonded to ten Mg and two equivalent Fe atoms to form MgMg10Fe2 cuboctahedra that share corners with four equivalent FeLi2Mg10 cuboctahedra, corners with six equivalent MgMg10Fe2 cuboctahedra, edges with two equivalent FeLi2Mg10 cuboctahedra, edges with four equivalent MgLi2Mg10 cuboctahedra, faces with two equivalent FeLi2Mg10 cuboctahedra, faces with four MgMg10Fe2 cuboctahedra, and faces with six equivalent LiMg10Fe2 cuboctahedra. There are four shorter (3.05 Å) and two longer (3.07 Å) Mg–Mg bond lengths. Both Mg–Fe bond lengths are 3.13 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Li, eight Mg, and two equivalent Fe atoms. There are a spread of Mg–Mg bond distances ranging from 2.93–3.33 Å. Both Mg–Fe bond lengths are 2.93 Å. In the fourth Mg site, Mg is bonded to two equivalent Li and ten Mg atoms to form MgLi2Mg10 cuboctahedra that share corners with four equivalent LiMg10Fe2 cuboctahedra, corners with six equivalent MgLi2Mg10 cuboctahedra, edges with two equivalent LiMg10Fe2 cuboctahedra, edges with four equivalent MgMg10Fe2 cuboctahedra, faces with two equivalent LiMg10Fe2 cuboctahedra, faces with four MgMg10Fe2 cuboctahedra, and faces with six equivalent FeLi2Mg10 cuboctahedra. Fe is bonded to two equivalent Li and ten Mg atoms to form FeLi2Mg10 cuboctahedra that share corners with four equivalent MgMg10Fe2 cuboctahedra, corners with six equivalent FeLi2Mg10 cuboctahedra, edges with two equivalent MgMg10Fe2 cuboctahedra, edges with four equivalent LiMg10Fe2 cuboctahedra, faces with two equivalent LiMg10Fe2 cuboctahedra, faces with two equivalent FeLi2Mg10 cuboctahedra, and faces with eight MgMg10Fe2 cuboctahedra.