Li3Fe2(PO4)3 crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to two equivalent O(6) and four equivalent O(5) atoms. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(3) atoms. Fe(1) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-60°. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-65°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(3), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Li(3), one Fe(1), and one P(1) atom to form distorted edge-sharing OLi2FeP trigonal pyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Li(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom.
Li3Fe2(PO4)3 crystallizes in the monoclinic C2/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted LiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. Both Li(1)-O(1) bond lengths are 2.23 Å. Both Li(1)-O(4) bond lengths are 2.41 Å. Both Li(1)-O(5) bond lengths are 2.12 Å. In the second Li site, Li(2) is bonded in a 6-coordinate geometry to two equivalent O(6) and four equivalent O(5) atoms. Both Li(2)-O(6) bond lengths are 2.26 Å. There are two shorter (2.14 Å) and two longer (2.53 Å) Li(2)-O(5) bond lengths. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(3) atoms. Both Li(3)-O(4) bond lengths are 2.39 Å. There are two shorter (2.21 Å) and two longer (2.42 Å) Li(3)-O(3) bond lengths. Fe(1) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra,  an edgeedge with one Li(1)O6 octahedra, and  an edgeedge with one Fe(1)O6 octahedra. The Fe(1)-O(1) bond length is 1.98 Å. The Fe(1)-O(3) bond length is 2.02 Å. The Fe(1)-O(4) bond length is 1.99 Å. The Fe(1)-O(6) bond length is 1.96 Å. There is one shorter (2.04 Å) and one longer (2.37 Å) Fe(1)-O(2) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-60°. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.59 Å. The P(1)-O(4) bond length is 1.57 Å. The P(1)-O(5) bond length is 1.52 Å. In the second P site, P(2) is bonded to two equivalent O(1) and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-65°. Both P(2)-O(1) bond lengths are 1.55 Å. Both P(2)-O(6) bond lengths are 1.56 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Fe(1), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(3), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Li(3), one Fe(1), and one P(1) atom to form distorted edge-sharing OLi2FeP trigonal pyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), two equivalent Li(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(2) atom.