Li3Fe3(PO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form LiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(8) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(6), one O(7), and one O(8) atom to form distorted FeO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 30-49°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and corners with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one P(2) atom. In the second O site, O(8) is bonded to one Li(1), one Li(2), one Fe(1), and one P(2) atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Fe(2), and one P(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Fe(2), and one P(1) atom. In the sixth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one Fe(1), and one P(1) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom.
Li3Fe3(PO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form LiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The Li(1)-O(2) bond length is 2.06 Å. The Li(1)-O(3) bond length is 2.18 Å. The Li(1)-O(4) bond length is 2.07 Å. The Li(1)-O(6) bond length is 2.06 Å. The Li(1)-O(8) bond length is 2.15 Å. In the second Li site, Li(2) is bonded in a square co-planar geometry to two equivalent O(7) and two equivalent O(8) atoms. Both Li(2)-O(7) bond lengths are 1.97 Å. Both Li(2)-O(8) bond lengths are 2.12 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), one O(6), one O(7), and one O(8) atom to form distorted FeO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. The Fe(1)-O(1) bond length is 1.87 Å. The Fe(1)-O(4) bond length is 2.05 Å. The Fe(1)-O(6) bond length is 1.95 Å. The Fe(1)-O(7) bond length is 2.17 Å. The Fe(1)-O(8) bond length is 1.97 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Li(1)O5 trigonal bipyramids. Both Fe(2)-O(2) bond lengths are 2.06 Å. Both Fe(2)-O(3) bond lengths are 2.18 Å. Both Fe(2)-O(5) bond lengths are 1.90 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with three equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 30-49°. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.53 Å. The P(1)-O(6) bond length is 1.58 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Li(1)O5 trigonal bipyramids, and corners with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. The P(2)-O(1) bond length is 1.55 Å. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.54 Å. The P(2)-O(8) bond length is 1.58 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one P(2) atom. In the second O site, O(8) is bonded to one Li(1), one Li(2), one Fe(1), and one P(2) atom to form distorted corner-sharing OLi2FeP trigonal pyramids. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Fe(2), and one P(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Li(1), one Fe(2), and one P(1) atom. In the sixth O site, O(4) is bonded in a distorted T-shaped geometry to one Li(1), one Fe(1), and one P(1) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom.