Materials Data on Li2Fe2B2O7 by Materials Project
Li2Fe2B2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two 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 1.95–2.38 Å. In the second Li1+ site, Li1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.01–2.53 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.89–2.25 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form distorted FeO4 tetrahedra that share corners with four BO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.88–1.96 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 a cornercorner with one BO4 tetrahedra and corners with two equivalent FeO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.43–1.54 Å. In the second B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share a cornercorner with one BO4 tetrahedra and corners with two equivalent FeO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.46–1.52 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Fe3+, and two B3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one B3+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Fe3+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe3+, and one B3+ atom. In the fifth O2- site, O2- is bonded to two Li1+, one Fe3+, and one B3+ atom to form corner-sharing OLi2FeB tetrahedra. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Fe3+, and one B3+ atom. In the seventh O2- site, O2- is bonded to one Li1+, two Fe3+, and one B3+ atom to form distorted corner-sharing OLiFe2B tetrahedra.