MnFe2(PO9)2 crystallizes in the triclinic P-1 space group. Mn(1) is bonded to one O(13), one O(14), one O(15), one O(16), one O(3), and one O(6) atom to form MnO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra and  a cornercorner with one P(2)O4 tetrahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(9) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 35°. In the second Fe site, Fe(2) is bonded to two equivalent O(10), two equivalent O(12), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. In the third Fe site, Fe(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-49°. 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  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-53°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(3) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(3) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(1) and one Fe(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(2) and one Fe(3) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Fe(1) and one O(17) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Fe(2) atom. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one Mn(1) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one Mn(1) and one O(18) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one Mn(1) atom. In the sixteenth O site, O(16) is bonded in a single-bond geometry to one Mn(1) atom. In the seventeenth O site, O(17) is bonded in a single-bond geometry to one O(11) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one O(14) atom.
MnFe2(PO9)2 crystallizes in the triclinic P-1 space group. Mn(1) is bonded to one O(13), one O(14), one O(15), one O(16), one O(3), and one O(6) atom to form MnO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra and  a cornercorner with one P(2)O4 tetrahedra. The Mn(1)-O(13) bond length is 1.84 Å. The Mn(1)-O(14) bond length is 1.74 Å. The Mn(1)-O(15) bond length is 1.79 Å. The Mn(1)-O(16) bond length is 2.03 Å. The Mn(1)-O(3) bond length is 1.94 Å. The Mn(1)-O(6) bond length is 1.93 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(9) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 35°. Both Fe(1)-O(11) bond lengths are 2.44 Å. Both Fe(1)-O(2) bond lengths are 1.87 Å. Both Fe(1)-O(9) bond lengths are 1.82 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(10), two equivalent O(12), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. Both Fe(2)-O(10) bond lengths are 1.85 Å. Both Fe(2)-O(12) bond lengths are 1.86 Å. Both Fe(2)-O(8) bond lengths are 1.96 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-49°. The Fe(3)-O(1) bond length is 1.97 Å. The Fe(3)-O(10) bond length is 1.94 Å. The Fe(3)-O(4) bond length is 2.07 Å. The Fe(3)-O(5) bond length is 2.04 Å. The Fe(3)-O(7) bond length is 1.99 Å. The Fe(3)-O(9) bond length is 1.88 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  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-53°. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.56 Å. The P(2)-O(7) bond length is 1.53 Å. The P(2)-O(8) bond length is 1.57 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Fe(3) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Fe(3) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(3) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(1) and one Fe(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Fe(2) and one Fe(3) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Fe(1) and one O(17) atom. The O(11)-O(17) bond length is 1.22 Å. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Fe(2) atom. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one Mn(1) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one Mn(1) and one O(18) atom. The O(14)-O(18) bond length is 2.03 Å. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one Mn(1) atom. In the sixteenth O site, O(16) is bonded in a single-bond geometry to one Mn(1) atom. In the seventeenth O site, O(17) is bonded in a single-bond geometry to one O(11) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one O(14) atom.