Li3Fe2(PO5)2 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra and edges with four equivalent Li(2)O6 octahedra. In the second Li site, Li(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. Fe(1) is bonded in a 5-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Li(1), two equivalent Li(2), and two equivalent Fe(1) atoms.
Li3Fe2(PO5)2 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra and edges with four equivalent Li(2)O6 octahedra. Both Li(1)-O(3) bond lengths are 2.21 Å. All Li(1)-O(2) bond lengths are 2.08 Å. In the second Li site, Li(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with two equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. Both Li(2)-O(1) bond lengths are 2.02 Å. Both Li(2)-O(2) bond lengths are 2.10 Å. Both Li(2)-O(3) bond lengths are 2.45 Å. Fe(1) is bonded in a 5-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Fe(1)-O(1) bond lengths are 1.99 Å. Both Fe(1)-O(2) bond lengths are 2.07 Å. There is one shorter (1.76 Å) and one longer (2.61 Å) Fe(1)-O(3) bond length. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra and corners with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. Both P(1)-O(1) bond lengths are 1.55 Å. Both P(1)-O(2) bond lengths are 1.55 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Li(1), two equivalent Li(2), and two equivalent Fe(1) atoms.