DOE OSTI2020
Li8Mg3Cu9(SiO3)16 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Li sites. In the first Li site, Li is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Li–O bond distances ranging from 1.97–2.46 Å. In the second Li site, Li is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Li–O bond distances ranging from 1.97–2.45 Å. In the third Li site, Li is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Li–O bond distances ranging from 1.96–2.46 Å. In the fourth Li site, Li is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Li–O bond distances ranging from 1.97–2.47 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with four CuO5 square pyramids. There are a spread of Mg–O bond distances ranging from 2.03–2.27 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with four CuO5 square pyramids. There are four shorter (2.04 Å) and two longer (2.26 Å) Mg–O bond lengths. There are five inequivalent Cu sites. In the first Cu site, Cu is bonded to five O atoms to form distorted CuO5 square pyramids that share corners with five SiO4 tetrahedra, edges with two MgO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.47 Å. In the second Cu site, Cu is bonded to five O atoms to form distorted CuO5 square pyramids that share corners with five SiO4 tetrahedra, edges with two MgO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.48 Å. In the third Cu site, Cu is bonded to five O atoms to form distorted CuO5 square pyramids that share corners with five SiO4 tetrahedra, an edgeedge with one MgO6 octahedra, an edgeedge with one CuO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.96–2.47 Å. In the fourth Cu site, Cu is bonded to five O atoms to form distorted CuO5 square pyramids that share corners with five SiO4 tetrahedra, an edgeedge with one MgO6 octahedra, an edgeedge with one CuO6 octahedra, and an edgeedge with one CuO5 square pyramid. There are a spread of Cu–O bond distances ranging from 1.94–2.48 Å. In the fifth Cu site, Cu is bonded to six O atoms to form CuO6 octahedra that share corners with six SiO4 tetrahedra and edges with four CuO5 square pyramids. There are four shorter (2.02 Å) and two longer (2.31 Å) Cu–O bond lengths. There are eight inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, corners with two CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two MgO6 octahedra, corners with three CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–52°. There is two shorter (1.63 Å) and two longer (1.68 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two MgO6 octahedra, corners with three CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–53°. There is two shorter (1.63 Å) and two longer (1.68 Å) Si–O bond length. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, corners with two equivalent CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, corners with two CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, a cornercorner with one CuO6 octahedra, corners with three CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–52°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, a cornercorner with one CuO6 octahedra, corners with three CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–53°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one CuO6 octahedra, corners with two equivalent CuO5 square pyramids, and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Li and two Si atoms. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to two Li and two Si atoms. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li and two Si atoms. In the fourth O site, O is bonded in a 3-coordinate geometry to one Mg, one Cu, and one Si atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one Li and two Si atoms. In the sixth O site, O is bonded in a 3-coordinate geometry to one Mg, one Cu, and one Si atom. In the seventh O site, O is bonded in a distorted rectangular see-saw-like geometry to one Mg, two Cu, and one Si atom. In the eighth O site, O is bonded in a 3-coordinate geometry to one Li, one Cu, and one Si atom. In the ninth O site, O is bonded to one Li, one Mg, one Cu, and one Si atom to form corner-sharing OLiMgCuSi tetrahedra. In the tenth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Mg, two Cu, and one Si atom. In the eleventh O site, O is bonded in a 3-coordinate geometry to one Li, one Cu, and one Si atom. In the twelfth O site, O is bonded to one Li, one Mg, one Cu, and one Si atom to form corner-sharing OLiMgCuSi tetrahedra. In the thirteenth O site, O is bonded in a 3-coordinate geometry to one Li and two Si atoms. In the fourteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Li and two Si atoms. In the fifteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li and two Si atoms. In the sixteenth O site, O is bonded in a 3-coordinate geometry to one Mg, one Cu, and one Si atom. In the seventeenth O site, O is bonded in a 3-coordinate geometry to one Li and two Si atoms. In the eighteenth O site, O is bonded in a 2-coordinate geometry to two Cu and one Si atom. In the nineteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Cu and one Si atom. In the twentieth O site, O is bonded in a 3-coordinate geometry to one Li, one Cu, and one Si atom. In the twenty-first O site, O is bonded to one Li, one Mg, one Cu, and one Si atom to form corner-sharing OLiMgCuSi tetrahedra. In the twenty-second O site, O is bonded in a distorted rectangular see-saw-like geometry to one Mg, two Cu, and one Si atom. In the twenty-third O site, O is bonded in a 3-coordinate geometry to one Li, one Cu, and one Si atom. In the twenty-fourth O site, O is bonded to one Li, two Cu, and one Si atom to form corner-sharing OLiCu2Si tetrahedra.