Li2FeBO4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent B(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent B(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. B(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form BO4 tetrahedra that share corners with four equivalent Li(2)O4 tetrahedra and corners with four equivalent Fe(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Fe(1), and one B(1) atom to form distorted OLiFe2B tetrahedra that share corners with two equivalent O(2)Li3B tetrahedra, corners with eight equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(1)LiFe2B tetrahedra. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), and one B(1) atom to form distorted OLi3B tetrahedra that share corners with two equivalent O(1)LiFe2B tetrahedra, corners with eight equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(2)Li3B tetrahedra. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(1), and one B(1) atom to form OLi2FeB trigonal pyramids that share corners with four equivalent O(2)Li3B tetrahedra, corners with four equivalent O(1)LiFe2B tetrahedra, corners with two equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(3)Li2FeB trigonal pyramid.
Li2FeBO4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Li(1)-O(1) bond length is 2.19 Å. The Li(1)-O(2) bond length is 1.92 Å. Both Li(1)-O(3) bond lengths are 2.02 Å. In the second Li site, Li(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent B(1)O4 tetrahedra, and  an edgeedge with one Li(2)O4 tetrahedra. Both Li(2)-O(2) bond lengths are 1.96 Å. Both Li(2)-O(3) bond lengths are 1.98 Å. Fe(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent B(1)O4 tetrahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. Both Fe(1)-O(1) bond lengths are 1.99 Å. Both Fe(1)-O(3) bond lengths are 1.86 Å. B(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form BO4 tetrahedra that share corners with four equivalent Li(2)O4 tetrahedra and corners with four equivalent Fe(1)O4 tetrahedra. The B(1)-O(1) bond length is 1.61 Å. The B(1)-O(2) bond length is 1.40 Å. Both B(1)-O(3) bond lengths are 1.52 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Fe(1), and one B(1) atom to form distorted OLiFe2B tetrahedra that share corners with two equivalent O(2)Li3B tetrahedra, corners with eight equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(1)LiFe2B tetrahedra. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), and one B(1) atom to form distorted OLi3B tetrahedra that share corners with two equivalent O(1)LiFe2B tetrahedra, corners with eight equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(2)Li3B tetrahedra. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(1), and one B(1) atom to form OLi2FeB trigonal pyramids that share corners with four equivalent O(2)Li3B tetrahedra, corners with four equivalent O(1)LiFe2B tetrahedra, corners with two equivalent O(3)Li2FeB trigonal pyramids, and  an edgeedge with one O(3)Li2FeB trigonal pyramid.