DOI: 10.17188/1300008
title: Materials Data on Li9Mn2AlO8 by Materials Project

description: Li9Mn2AlO8 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are six inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two MnO4 tetrahedra, corners with two equivalent AlO4 tetrahedra, corners with five LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, an edgeedge with one MnO4 tetrahedra, and edges with two LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.90–2.08 Å. In the second Li1+ site, Li1+ is bonded in a 1-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.93–2.38 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share a cornercorner with one AlO4 tetrahedra, corners with four MnO4 tetrahedra, corners with six LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, and an edgeedge with one AlO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.90–2.14 Å. In the fourth Li1+ site, Li1+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.82 Å) and two longer (1.92 Å) Li–O bond length. In the fifth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra, corners with two equivalent MnO4 tetrahedra, corners with four LiO4 tetrahedra, corners with four equivalent LiO4 trigonal pyramids, an edgeedge with one MnO4 tetrahedra, and edges with two equivalent LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.93–2.36 Å. In the sixth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two MnO4 tetrahedra, corners with seven LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, an edgeedge with one MnO4 tetrahedra, and edges with two LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.03–2.09 Å. There are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four O2- atoms to form distorted MnO4 tetrahedra that share corners with three equivalent AlO4 tetrahedra, corners with four LiO4 tetrahedra, corners with four equivalent LiO4 trigonal pyramids, and edges with three LiO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.06–2.13 Å. In the second Mn2+ site, Mn2+ is bonded to four O2- atoms to form distorted MnO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra, corners with six LiO4 tetrahedra, corners with four equivalent LiO4 trigonal pyramids, and edges with two equivalent LiO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.02–2.10 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four MnO4 tetrahedra, corners with five LiO4 tetrahedra, corners with two equivalent LiO4 trigonal pyramids, and edges with two equivalent LiO4 trigonal pyramids. There is three shorter (1.80 Å) and one longer (1.83 Å) Al–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Li1+, one Mn2+, and one Al3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one Mn2+, and one Al3+ atom. In the third O2- site, O2- is bonded in a 7-coordinate geometry to six Li1+ and one Mn2+ atom. In the fourth O2- site, O2- is bonded to five Li1+ and one Mn2+ atom to form distorted corner-sharing OLi5Mn octahedra. In the fifth O2- site, O2- is bonded to two equivalent Li1+, one Mn2+, and one Al3+ atom to form distorted corner-sharing OLi2MnAl tetrahedra. The corner-sharing octahedral tilt angles are 79°. In the sixth O2- site, O2- is bonded in a 7-coordinate geometry to six Li1+ and one Mn2+ atom.