Fe2P3O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(13), one O(3), one O(6), and one O(8) atom to form distorted FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(11), one O(12), one O(2), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(11), one O(2), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-43°. In the second P site, P(2) is bonded to one O(13), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-53°. In the third P site, P(3) is bonded to one O(10), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-51°. There are thirteen inequivalent O sites. In the first O site, O(13) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(1) is bonded in a linear geometry to one Fe(1) and one P(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the seventh O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(1) and one O(8) atom. In the tenth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eleventh O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the twelfth O site, O(11) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the thirteenth O site, O(12) is bonded in a single-bond geometry to one Fe(2) atom.
Fe2P3O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(13), one O(3), one O(6), and one O(8) atom to form distorted FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The Fe(1)-O(1) bond length is 2.01 Å. The Fe(1)-O(10) bond length is 1.99 Å. The Fe(1)-O(13) bond length is 2.03 Å. The Fe(1)-O(3) bond length is 1.90 Å. The Fe(1)-O(6) bond length is 1.98 Å. The Fe(1)-O(8) bond length is 2.53 Å. In the second Fe site, Fe(2) is bonded to one O(11), one O(12), one O(2), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The Fe(2)-O(11) bond length is 1.98 Å. The Fe(2)-O(12) bond length is 2.02 Å. The Fe(2)-O(2) bond length is 2.05 Å. The Fe(2)-O(5) bond length is 1.98 Å. The Fe(2)-O(7) bond length is 1.93 Å. The Fe(2)-O(9) bond length is 2.00 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(11), one O(2), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra and corners with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-43°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(11) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(9) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(13), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-53°. The P(2)-O(13) bond length is 1.53 Å. The P(2)-O(4) bond length is 1.62 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(7) bond length is 1.52 Å. In the third P site, P(3) is bonded to one O(10), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-51°. The P(3)-O(10) bond length is 1.53 Å. The P(3)-O(3) bond length is 1.54 Å. The P(3)-O(4) bond length is 1.64 Å. The P(3)-O(5) bond length is 1.52 Å. There are thirteen inequivalent O sites. In the first O site, O(13) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the second O site, O(1) is bonded in a linear geometry to one Fe(1) and one P(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Fe(2) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the seventh O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(1) and one O(8) atom. The O(8)-O(8) bond length is 1.23 Å. In the tenth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the eleventh O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the twelfth O site, O(11) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(1) atom. In the thirteenth O site, O(12) is bonded in a single-bond geometry to one Fe(2) atom.