CsFe2P5O16 crystallizes in the monoclinic Pc space group. Cs(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(14), one O(2), one O(3), one O(8), and one O(9) atom. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(14), one O(16), one O(3), one O(6), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(5)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(13), one O(2), one O(5), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. There are five 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  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-47°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-51°. In the third P site, P(3) is bonded to one O(15), one O(16), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 7-58°. In the fourth P site, P(4) is bonded to one O(12), one O(13), one O(14), and one O(15) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the fifth P site, P(5) is bonded to one O(10), one O(11), one O(12), and one O(9) 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(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-43°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Cs(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Cs(1), one Fe(2), and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(1), and one P(5) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(5) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(1), and one P(5) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(4) and one P(5) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Fe(1), and one P(4) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(3) and one P(4) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to one Fe(1) and one P(3) atom.
CsFe2P5O16 crystallizes in the monoclinic Pc space group. Cs(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(14), one O(2), one O(3), one O(8), and one O(9) atom. The Cs(1)-O(1) bond length is 3.28 Å. The Cs(1)-O(11) bond length is 3.40 Å. The Cs(1)-O(14) bond length is 3.25 Å. The Cs(1)-O(2) bond length is 3.38 Å. The Cs(1)-O(3) bond length is 3.29 Å. The Cs(1)-O(8) bond length is 3.17 Å. The Cs(1)-O(9) bond length is 3.44 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(14), one O(16), one O(3), one O(6), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(5)O4 tetrahedra. The Fe(1)-O(11) bond length is 2.00 Å. The Fe(1)-O(14) bond length is 2.02 Å. The Fe(1)-O(16) bond length is 2.15 Å. The Fe(1)-O(3) bond length is 1.95 Å. The Fe(1)-O(6) bond length is 2.07 Å. The Fe(1)-O(9) bond length is 2.03 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(13), one O(2), one O(5), and one O(8) atom to form FeO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Fe(2)-O(1) bond length is 1.97 Å. The Fe(2)-O(10) bond length is 1.98 Å. The Fe(2)-O(13) bond length is 2.03 Å. The Fe(2)-O(2) bond length is 1.98 Å. The Fe(2)-O(5) bond length is 2.12 Å. The Fe(2)-O(8) bond length is 2.09 Å. There are five 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  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-47°. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.65 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-51°. The P(2)-O(4) bond length is 1.60 Å. The P(2)-O(5) bond length is 1.50 Å. The P(2)-O(6) bond length is 1.51 Å. The P(2)-O(7) bond length is 1.63 Å. In the third P site, P(3) is bonded to one O(15), one O(16), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 7-58°. The P(3)-O(15) bond length is 1.62 Å. The P(3)-O(16) bond length is 1.49 Å. The P(3)-O(7) bond length is 1.62 Å. The P(3)-O(8) bond length is 1.51 Å. In the fourth P site, P(4) is bonded to one O(12), one O(13), one O(14), and one O(15) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-52°. The P(4)-O(12) bond length is 1.58 Å. The P(4)-O(13) bond length is 1.50 Å. The P(4)-O(14) bond length is 1.52 Å. The P(4)-O(15) bond length is 1.62 Å. In the fifth P site, P(5) is bonded to one O(10), one O(11), one O(12), and one O(9) 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(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 26-43°. The P(5)-O(10) bond length is 1.52 Å. The P(5)-O(11) bond length is 1.53 Å. The P(5)-O(12) bond length is 1.65 Å. The P(5)-O(9) bond length is 1.53 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(2), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Cs(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Cs(1), one Fe(2), and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(1), and one P(5) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Fe(2) and one P(5) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Fe(1), and one P(5) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(4) and one P(5) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Fe(1), and one P(4) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one P(3) and one P(4) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to one Fe(1) and one P(3) atom.