DOE OSTI2020
Li2Sn(BO3)2 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share corners with two equivalent SnO6 octahedra, a cornercorner with one SnO7 pentagonal bipyramid, and a cornercorner with one LiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 71–79°. There are a spread of Li–O bond distances ranging from 1.89–2.03 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 1.90–2.12 Å. In the third 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 1.83–2.69 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with three equivalent SnO7 pentagonal bipyramids, and a cornercorner with one LiO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Li–O bond distances ranging from 1.91–2.22 Å. There are four inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.36 Å) and two longer (1.41 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.38 Å) and one longer (1.41 Å) B–O bond length. In the third B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.36–1.41 Å. In the fourth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.34 Å) and two longer (1.41 Å) B–O bond length. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with three LiO4 tetrahedra and an edgeedge with one SnO7 pentagonal bipyramid. There are a spread of Sn–O bond distances ranging from 2.05–2.19 Å. In the second Sn4+ site, Sn4+ is bonded to seven O2- atoms to form distorted SnO7 pentagonal bipyramids that share corners with four LiO4 tetrahedra and an edgeedge with one SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.08–2.37 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one B3+, and one Sn4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one B3+, and one Sn4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one B3+, and one Sn4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Li1+, one B3+, and one Sn4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Li1+, one B3+, and one Sn4+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one B3+, and two Sn4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Li1+ and one B3+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one B3+, and one Sn4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one B3+, and one Sn4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one B3+, and one Sn4+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one B3+, and one Sn4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one B3+ and two Sn4+ atoms.