LiFe2(PO4)2 crystallizes in the monoclinic Cm space group. Li(1) is bonded to one O(1), one O(3), and two equivalent O(5) atoms to form distorted LiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 71-78°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with two equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-54°. In the second P site, P(2) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-56°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom.
LiFe2(PO4)2 crystallizes in the monoclinic Cm space group. Li(1) is bonded to one O(1), one O(3), and two equivalent O(5) atoms to form distorted LiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 71-78°. The Li(1)-O(1) bond length is 2.05 Å. The Li(1)-O(3) bond length is 2.00 Å. Both Li(1)-O(5) bond lengths are 2.11 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. The Fe(1)-O(1) bond length is 2.00 Å. The Fe(1)-O(6) bond length is 1.94 Å. Both Fe(1)-O(2) bond lengths are 2.03 Å. Both Fe(1)-O(5) bond lengths are 2.17 Å. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. The Fe(2)-O(3) bond length is 2.08 Å. The Fe(2)-O(4) bond length is 2.03 Å. Both Fe(2)-O(2) bond lengths are 2.20 Å. Both Fe(2)-O(5) bond lengths are 2.29 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and corners with two equivalent Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-54°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.53 Å. Both P(1)-O(2) bond lengths are 1.57 Å. In the second P site, P(2) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-56°. The P(2)-O(4) bond length is 1.51 Å. The P(2)-O(6) bond length is 1.53 Å. Both P(2)-O(5) bond lengths are 1.59 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Fe(1), one Fe(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom.