DOE OSTI2020
Li2Cr(Si2O5)3 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first 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 2.04–2.44 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 2.05–2.44 Å. There are two inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six SiO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.94–1.97 Å. In the second Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six SiO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.94–1.98 Å. There are eight inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Si–O bond distances ranging from 1.59–1.65 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 22°. There are a spread of Si–O bond distances ranging from 1.59–1.65 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CrO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 21°. There are a spread of Si–O bond distances ranging from 1.60–1.65 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Li1+, one Cr4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Li1+, one Cr4+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr4+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr4+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Cr4+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Li1+, one Cr4+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Li1+, one Cr4+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms.