DOE OSTI2020
Li2CoSiO4 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.99–2.60 Å. In the second Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.94–2.21 Å. In the third Li1+ site, Li1+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Li–O bond distances ranging from 1.93–1.97 Å. In the fourth Li1+ site, Li1+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Li–O bond distances ranging from 1.96–2.05 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with four SiO4 tetrahedra. There is one shorter (1.97 Å) and three longer (2.00 Å) Co–O bond length. In the second Co2+ site, Co2+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Co–O bond distances ranging from 1.94–2.00 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four CoO4 tetrahedra. There is one shorter (1.65 Å) and three longer (1.66 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four CoO4 tetrahedra. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form corner-sharing OLi2CoSi tetrahedra. In the second O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form distorted corner-sharing OLi2CoSi trigonal pyramids. In the third O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLi2CoSi trigonal pyramids. In the fourth O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLi2CoSi trigonal pyramids. In the fifth O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form distorted corner-sharing OLi2CoSi trigonal pyramids. In the sixth O2- site, O2- is bonded to two Li1+, one Co2+, and one Si4+ atom to form corner-sharing OLi2CoSi tetrahedra. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+, one Co2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Co2+, and one Si4+ atom.