Materials Data on LiMgAsO4 by Materials Project
LiMgAsO4 is Spinel-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four equivalent MgO6 octahedra, corners with two equivalent AsO4 tetrahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent MgO6 octahedra, and edges with two equivalent AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 2.13–2.28 Å. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four equivalent LiO6 octahedra, corners with four equivalent MgO6 octahedra, corners with four equivalent AsO4 tetrahedra, edges with two equivalent LiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–63°. There are a spread of Mg–O bond distances ranging from 2.08–2.22 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent LiO6 octahedra, corners with four equivalent MgO6 octahedra, an edgeedge with one MgO6 octahedra, and edges with two equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of As–O bond distances ranging from 1.71–1.74 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two equivalent Mg2+, and one As5+ atom. In the second O2- site, O2- is bonded to two equivalent Li1+, one Mg2+, and one As5+ atom to form distorted corner-sharing OLi2MgAs trigonal pyramids. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Li1+, one Mg2+, and one As5+ atom.