Fe5P3O17 crystallizes in the orthorhombic Ama2 space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-51°. In the third Fe site, Fe(3) is bonded to one O(10), one O(3), one O(4), one O(5), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-47°. In the second P site, P(2) is bonded to one O(6), one O(7), and two equivalent O(9) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-55°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the second O site, O(10) is bonded in a bent 150 degrees geometry to two equivalent Fe(3) atoms. In the third 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 fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Fe(3) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one P(2) atom. In the eighth O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one P(2) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the tenth O site, O(9) is bonded in a bent 120 degrees geometry to one Fe(3) and one P(2) atom.
Fe5P3O17 crystallizes in the orthorhombic Ama2 space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and faces with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. Both Fe(1)-O(1) bond lengths are 2.04 Å. Both Fe(1)-O(2) bond lengths are 2.09 Å. Both Fe(1)-O(8) bond lengths are 2.01 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-51°. The Fe(2)-O(1) bond length is 2.15 Å. The Fe(2)-O(2) bond length is 2.05 Å. The Fe(2)-O(5) bond length is 1.97 Å. The Fe(2)-O(6) bond length is 2.06 Å. The Fe(2)-O(7) bond length is 2.08 Å. The Fe(2)-O(8) bond length is 1.99 Å. In the third Fe site, Fe(3) is bonded to one O(10), one O(3), one O(4), one O(5), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. The Fe(3)-O(10) bond length is 1.95 Å. The Fe(3)-O(3) bond length is 1.98 Å. The Fe(3)-O(4) bond length is 1.95 Å. The Fe(3)-O(5) bond length is 2.11 Å. The Fe(3)-O(8) bond length is 2.04 Å. The Fe(3)-O(9) bond length is 1.97 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-47°. The P(1)-O(1) bond length is 1.58 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(6), one O(7), and two equivalent O(9) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with four equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-55°. The P(2)-O(6) bond length is 1.57 Å. The P(2)-O(7) bond length is 1.59 Å. Both P(2)-O(9) bond lengths are 1.52 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one P(1) atom. In the second O site, O(10) is bonded in a bent 150 degrees geometry to two equivalent Fe(3) atoms. In the third 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 fourth O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one Fe(3) atom. In the seventh O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one P(2) atom. In the eighth O site, O(7) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one P(2) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the tenth O site, O(9) is bonded in a bent 120 degrees geometry to one Fe(3) and one P(2) atom.