DOI: 10.17188/1745390
title: Materials Data on Li4Mn9O18 by Materials Project

description: Li4Mn9O18 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.22–2.64 Å. In the second Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.20–2.55 Å. There are five inequivalent Mn+3.56+ sites. In the first Mn+3.56+ site, Mn+3.56+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There is two shorter (1.93 Å) and four longer (2.03 Å) Mn–O bond length. In the second Mn+3.56+ site, Mn+3.56+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.94–2.09 Å. In the third Mn+3.56+ site, Mn+3.56+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–68°. There are four shorter (1.97 Å) and one longer (2.10 Å) Mn–O bond lengths. In the fourth Mn+3.56+ site, Mn+3.56+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.92–1.96 Å. In the fifth Mn+3.56+ site, Mn+3.56+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MnO5 square pyramids and edges with four MnO6 octahedra. There is two shorter (1.93 Å) and four longer (1.94 Å) Mn–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.56+ atoms to form OLi2Mn3 square pyramids that share corners with two equivalent OLi2Mn3 square pyramids, edges with three equivalent OLi2Mn3 square pyramids, and edges with two equivalent OLiMn3 trigonal pyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.56+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.56+ atoms. In the fourth O2- site, O2- is bonded to one Li1+ and three Mn+3.56+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, corners with two equivalent OLiMn3 trigonal pyramids, and edges with two equivalent OLi2Mn3 square pyramids. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn+3.56+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Li1+ and two equivalent Mn+3.56+ atoms. In the seventh O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.56+ atoms to form distorted OLi2Mn3 trigonal bipyramids that share corners with six OLiMn3 trigonal pyramids and edges with two equivalent OLi2Mn3 trigonal bipyramids. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.56+ atoms. In the ninth O2- site, O2- is bonded to one Li1+ and three Mn+3.56+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four equivalent OLi2Mn3 trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids.