Li9(FeO4)2 is Aluminum carbonitride-like structured and crystallizes in the monoclinic C2 space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(2)O4 tetrahedra, edges with two equivalent Li(2)O4 tetrahedra, and edges with two equivalent Li(6)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with two equivalent Li(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Li(4)O4 tetrahedra, edges with two equivalent Li(3)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(6)O4 tetrahedra, edges with two equivalent Li(2)O4 tetrahedra, and edges with two equivalent Li(5)O4 trigonal pyramids. In the fourth Li site, Li(4) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(2)O4 tetrahedra, and edges with two equivalent Li(2)O4 tetrahedra. In the fifth Li site, Li(5) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Li(6)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Fe(1)O4 tetrahedra, and edges with two equivalent Li(3)O4 tetrahedra. In the sixth Li site, Li(6) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(1)O4 tetrahedra, edges with two equivalent Li(3)O4 tetrahedra, and edges with two equivalent Li(1)O4 trigonal pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(6)O4 tetrahedra, and edges with two equivalent Li(5)O4 trigonal pyramids. In the second Fe site, Fe(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(6)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Li(4)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Li(3), one Li(5), one Li(6), and one Fe(2) atom to form distorted OLi5Fe octahedra that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid,  a cornercorner with one O(2)Li4Fe trigonal bipyramid, corners with three equivalent O(4)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra, edges with three equivalent O(3)Li5Fe pentagonal pyramids,  an edgeedge with one O(2)Li4Fe trigonal bipyramid, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), and one Fe(1) atom to form distorted OLi4Fe trigonal bipyramids that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid, corners with two equivalent O(2)Li4Fe trigonal bipyramids, corners with three equivalent O(4)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra, edges with two equivalent O(3)Li5Fe pentagonal pyramids, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Li(5), one Li(6), and one Fe(1) atom to form distorted OLi5Fe pentagonal pyramids that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid,  a cornercorner with one O(2)Li4Fe trigonal bipyramid,  a cornercorner with one O(4)Li4Fe trigonal bipyramid, edges with three equivalent O(1)Li5Fe octahedra,  an edgeedge with one O(3)Li5Fe pentagonal pyramid,  an edgeedge with one O(4)Li4Fe trigonal bipyramid, and edges with two equivalent O(2)Li4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles are 68°. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), and one Fe(2) atom to form distorted OLi4Fe trigonal bipyramids that share corners with three equivalent O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid, corners with three equivalent O(2)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra,  an edgeedge with one O(3)Li5Fe pentagonal pyramid,  an edgeedge with one O(2)Li4Fe trigonal bipyramid, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-72°.
Li9(FeO4)2 is Aluminum carbonitride-like structured and crystallizes in the monoclinic C2 space group. There are six inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(2)O4 tetrahedra, edges with two equivalent Li(2)O4 tetrahedra, and edges with two equivalent Li(6)O4 tetrahedra. Both Li(1)-O(1) bond lengths are 2.08 Å. Both Li(1)-O(3) bond lengths are 2.04 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with two equivalent Li(6)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Li(4)O4 tetrahedra, edges with two equivalent Li(3)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. The Li(2)-O(1) bond length is 2.03 Å. The Li(2)-O(2) bond length is 2.02 Å. The Li(2)-O(3) bond length is 1.98 Å. The Li(2)-O(4) bond length is 1.97 Å. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(6)O4 tetrahedra, edges with two equivalent Li(2)O4 tetrahedra, and edges with two equivalent Li(5)O4 trigonal pyramids. The Li(3)-O(1) bond length is 1.98 Å. The Li(3)-O(2) bond length is 1.93 Å. The Li(3)-O(3) bond length is 2.06 Å. The Li(3)-O(4) bond length is 1.86 Å. In the fourth Li site, Li(4) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(2)O4 tetrahedra, and edges with two equivalent Li(2)O4 tetrahedra. Both Li(4)-O(2) bond lengths are 2.06 Å. Both Li(4)-O(4) bond lengths are 2.02 Å. In the fifth Li site, Li(5) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Li(6)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Fe(1)O4 tetrahedra, and edges with two equivalent Li(3)O4 tetrahedra. The Li(5)-O(1) bond length is 2.07 Å. The Li(5)-O(2) bond length is 2.06 Å. The Li(5)-O(3) bond length is 2.07 Å. The Li(5)-O(4) bond length is 2.02 Å. In the sixth Li site, Li(6) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted LiO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Fe(1)O4 tetrahedra, edges with two equivalent Li(3)O4 tetrahedra, and edges with two equivalent Li(1)O4 trigonal pyramids. Both Li(6)-O(1) bond lengths are 1.89 Å. Both Li(6)-O(3) bond lengths are 1.97 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids,  an edgeedge with one Li(6)O4 tetrahedra, and edges with two equivalent Li(5)O4 trigonal pyramids. Both Fe(1)-O(2) bond lengths are 1.83 Å. Both Fe(1)-O(3) bond lengths are 1.89 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form FeO4 tetrahedra that share corners with two equivalent Li(6)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Li(3)O4 tetrahedra, corners with four equivalent Li(5)O4 trigonal pyramids,  an edgeedge with one Li(4)O4 tetrahedra, and  an edgeedge with one Li(1)O4 trigonal pyramid. Both Fe(2)-O(1) bond lengths are 1.93 Å. Both Fe(2)-O(4) bond lengths are 1.88 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Li(3), one Li(5), one Li(6), and one Fe(2) atom to form distorted OLi5Fe octahedra that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid,  a cornercorner with one O(2)Li4Fe trigonal bipyramid, corners with three equivalent O(4)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra, edges with three equivalent O(3)Li5Fe pentagonal pyramids,  an edgeedge with one O(2)Li4Fe trigonal bipyramid, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles are 45°. In the second O site, O(2) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), and one Fe(1) atom to form distorted OLi4Fe trigonal bipyramids that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid, corners with two equivalent O(2)Li4Fe trigonal bipyramids, corners with three equivalent O(4)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra, edges with two equivalent O(3)Li5Fe pentagonal pyramids, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Li(5), one Li(6), and one Fe(1) atom to form distorted OLi5Fe pentagonal pyramids that share  a cornercorner with one O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid,  a cornercorner with one O(2)Li4Fe trigonal bipyramid,  a cornercorner with one O(4)Li4Fe trigonal bipyramid, edges with three equivalent O(1)Li5Fe octahedra,  an edgeedge with one O(3)Li5Fe pentagonal pyramid,  an edgeedge with one O(4)Li4Fe trigonal bipyramid, and edges with two equivalent O(2)Li4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles are 68°. In the fourth O site, O(4) is bonded to one Li(2), one Li(3), one Li(4), one Li(5), and one Fe(2) atom to form distorted OLi4Fe trigonal bipyramids that share corners with three equivalent O(1)Li5Fe octahedra,  a cornercorner with one O(3)Li5Fe pentagonal pyramid, corners with three equivalent O(2)Li4Fe trigonal bipyramids,  an edgeedge with one O(1)Li5Fe octahedra,  an edgeedge with one O(3)Li5Fe pentagonal pyramid,  an edgeedge with one O(2)Li4Fe trigonal bipyramid, and  an edgeedge with one O(4)Li4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-72°.