Li4Y3FeO8 crystallizes in the orthorhombic C222 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Li site, Li(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the third Li site, Li(3) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and edges with four equivalent Y(2)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. In the second Y site, Y(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Y(2)O6 octahedra, edges with two equivalent Y(1)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-22°. Fe(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Y(1)O6 octahedra and edges with four equivalent Y(2)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(3), one Y(1), and two equivalent Y(2) atoms to form OLi2Y3 square pyramids that share  a cornercorner with one O(1)Li2Y3 square pyramid, corners with four equivalent O(2)Li2Y2Fe square pyramids, corners with four equivalent O(3)Li2Y2Fe square pyramids, edges with two equivalent O(2)Li2Y2Fe square pyramids, edges with two equivalent O(3)Li2Y2Fe square pyramids, and edges with two equivalent O(1)Li2Y3 square pyramids. In the second O site, O(2) is bonded to two equivalent Li(3), two equivalent Y(2), and one Fe(1) atom to form OLi2Y2Fe square pyramids that share  a cornercorner with one O(2)Li2Y2Fe square pyramid, corners with four equivalent O(3)Li2Y2Fe square pyramids, corners with four equivalent O(1)Li2Y3 square pyramids, edges with two equivalent O(2)Li2Y2Fe square pyramids, edges with two equivalent O(3)Li2Y2Fe square pyramids, and edges with two equivalent O(1)Li2Y3 square pyramids. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Y(1), one Y(2), and one Fe(1) atom to form distorted OLi2Y2Fe square pyramids that share corners with two equivalent O(2)Li2Y2Fe square pyramids, corners with two equivalent O(1)Li2Y3 square pyramids, corners with five equivalent O(3)Li2Y2Fe square pyramids,  an edgeedge with one O(2)Li2Y2Fe square pyramid,  an edgeedge with one O(1)Li2Y3 square pyramid, and edges with four equivalent O(3)Li2Y2Fe square pyramids.
Li4Y3FeO8 crystallizes in the orthorhombic C222 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Li(1)-O(3) bond lengths are 2.22 Å. In the second Li site, Li(2) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Li(2)-O(3) bond lengths are 2.18 Å. In the third Li site, Li(3) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Li(3)-O(1) bond lengths are 2.20 Å. Both Li(3)-O(2) bond lengths are 2.23 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and edges with four equivalent Y(2)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. Both Y(1)-O(1) bond lengths are 2.26 Å. All Y(1)-O(3) bond lengths are 2.28 Å. In the second Y site, Y(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Y(2)O6 octahedra, edges with two equivalent Y(1)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-22°. Both Y(2)-O(1) bond lengths are 2.24 Å. Both Y(2)-O(2) bond lengths are 2.20 Å. Both Y(2)-O(3) bond lengths are 2.35 Å. Fe(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Y(1)O6 octahedra and edges with four equivalent Y(2)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. Both Fe(1)-O(2) bond lengths are 2.11 Å. All Fe(1)-O(3) bond lengths are 2.11 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(3), one Y(1), and two equivalent Y(2) atoms to form OLi2Y3 square pyramids that share  a cornercorner with one O(1)Li2Y3 square pyramid, corners with four equivalent O(2)Li2Y2Fe square pyramids, corners with four equivalent O(3)Li2Y2Fe square pyramids, edges with two equivalent O(2)Li2Y2Fe square pyramids, edges with two equivalent O(3)Li2Y2Fe square pyramids, and edges with two equivalent O(1)Li2Y3 square pyramids. In the second O site, O(2) is bonded to two equivalent Li(3), two equivalent Y(2), and one Fe(1) atom to form OLi2Y2Fe square pyramids that share  a cornercorner with one O(2)Li2Y2Fe square pyramid, corners with four equivalent O(3)Li2Y2Fe square pyramids, corners with four equivalent O(1)Li2Y3 square pyramids, edges with two equivalent O(2)Li2Y2Fe square pyramids, edges with two equivalent O(3)Li2Y2Fe square pyramids, and edges with two equivalent O(1)Li2Y3 square pyramids. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Y(1), one Y(2), and one Fe(1) atom to form distorted OLi2Y2Fe square pyramids that share corners with two equivalent O(2)Li2Y2Fe square pyramids, corners with two equivalent O(1)Li2Y3 square pyramids, corners with five equivalent O(3)Li2Y2Fe square pyramids,  an edgeedge with one O(2)Li2Y2Fe square pyramid,  an edgeedge with one O(1)Li2Y3 square pyramid, and edges with four equivalent O(3)Li2Y2Fe square pyramids.