DOI: 10.17188/1297193
title: Materials Data on Li2Si2NiO6 by Materials Project

description: Li2NiSi2O6 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 2-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.82–2.31 Å. In the second Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.16–2.49 Å. In the third Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 square pyramids that share a cornercorner with one NiO6 octahedra, a cornercorner with one LiO5 square pyramid, corners with four SiO4 tetrahedra, an edgeedge with one NiO6 octahedra, an edgeedge with one SiO4 tetrahedra, and a faceface with one NiO6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are a spread of Li–O bond distances ranging from 2.05–2.37 Å. In the fourth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.04–2.74 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six SiO4 tetrahedra, edges with two equivalent LiO5 square pyramids, and faces with two NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.01–2.16 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent LiO5 square pyramids, corners with six SiO4 tetrahedra, and a faceface with one NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.07–2.33 Å. In the third Ni2+ site, Ni2+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with six SiO4 tetrahedra, a faceface with one NiO6 octahedra, and faces with two equivalent LiO5 square pyramids. There are a spread of Ni–O bond distances ranging from 2.04–2.34 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three NiO6 octahedra, corners with two equivalent LiO5 square pyramids, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–56°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three NiO6 octahedra, corners with two equivalent LiO5 square pyramids, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–57°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three NiO6 octahedra, a cornercorner with one LiO5 square pyramid, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–46°. There is three shorter (1.62 Å) and one longer (1.65 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three NiO6 octahedra, a cornercorner with one LiO5 square pyramid, corners with two SiO4 tetrahedra, and an edgeedge with one LiO5 square pyramid. The corner-sharing octahedra tilt angles range from 42–44°. There is three shorter (1.62 Å) and one longer (1.66 Å) Si–O bond length. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+, two Ni2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Li1+, two Ni2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to two Li1+, two Ni2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded to two Li1+ and two Si4+ atoms to form a mixture of distorted edge and corner-sharing OLi2Si2 trigonal pyramids. In the seventh O2- site, O2- is bonded to two Li1+ and two Si4+ atoms to form distorted OLi2Si2 tetrahedra that share a cornercorner with one OLi2SiNi tetrahedra, corners with two equivalent OLi2Si2 trigonal pyramids, and an edgeedge with one OLi2Si2 tetrahedra. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Ni2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one Ni2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded to two Li1+, one Ni2+, and one Si4+ atom to form distorted corner-sharing OLi2SiNi tetrahedra. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to one Li1+ and two Si4+ atoms.