DOE OSTI2020
Li2FeBO4 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 4-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.93–2.47 Å. In the second Li1+ site, Li1+ is bonded to five O2- atoms to form distorted LiO5 trigonal bipyramids that share corners with five BO4 tetrahedra, a cornercorner with one FeO4 trigonal pyramid, and an edgeedge with one FeO4 trigonal pyramid. There are a spread of Li–O bond distances ranging from 1.96–2.15 Å. In the third Li1+ site, Li1+ is bonded in a 3-coordinate geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 2.03–2.53 Å. In the fourth 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 1.99–2.12 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 1.90–2.50 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form distorted FeO4 trigonal pyramids that share corners with two equivalent BO4 tetrahedra, a cornercorner with one LiO5 trigonal bipyramid, and an edgeedge with one LiO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.89–1.96 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with two equivalent BO4 tetrahedra and corners with two equivalent LiO5 trigonal bipyramids. There are a spread of B–O bond distances ranging from 1.48–1.52 Å. In the second B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with two equivalent BO4 tetrahedra, corners with three equivalent LiO5 trigonal bipyramids, and corners with two equivalent FeO4 trigonal pyramids. There are a spread of B–O bond distances ranging from 1.47–1.51 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one B3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one Fe3+, and one B3+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Li1+ and two B3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+ and two Fe3+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to two Li1+ and two B3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+ and three Fe3+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one B3+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one B3+ atom.