Mn3(AsO7)2 crystallizes in the triclinic P1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one As(1)O4 tetrahedra and  a cornercorner with one As(2)O4 tetrahedra. In the second Mn site, Mn(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Mn(3)O6 octahedra. In the third Mn site, Mn(3) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-61°. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-58°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(2) and one As(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(2) and one As(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(2), one Mn(3), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(2), one Mn(3), and one As(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(3) and one As(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(3) and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mn(1) and one As(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one As(2) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Mn(2) and one Mn(3) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one Mn(2) and one Mn(3) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Mn(1) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Mn(1) 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) atom.
Mn3(AsO7)2 crystallizes in the triclinic P1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one As(1)O4 tetrahedra and  a cornercorner with one As(2)O4 tetrahedra. The Mn(1)-O(11) bond length is 1.70 Å. The Mn(1)-O(12) bond length is 1.78 Å. The Mn(1)-O(13) bond length is 1.93 Å. The Mn(1)-O(14) bond length is 1.60 Å. The Mn(1)-O(7) bond length is 1.97 Å. The Mn(1)-O(8) bond length is 2.08 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Mn(3)O6 octahedra. The Mn(2)-O(1) bond length is 1.92 Å. The Mn(2)-O(10) bond length is 1.88 Å. The Mn(2)-O(2) bond length is 1.94 Å. The Mn(2)-O(3) bond length is 2.01 Å. The Mn(2)-O(4) bond length is 1.99 Å. The Mn(2)-O(9) bond length is 1.87 Å. In the third Mn site, Mn(3) is bonded to one O(10), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form MnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. The Mn(3)-O(10) bond length is 1.86 Å. The Mn(3)-O(3) bond length is 2.01 Å. The Mn(3)-O(4) bond length is 1.99 Å. The Mn(3)-O(5) bond length is 1.93 Å. The Mn(3)-O(6) bond length is 1.94 Å. The Mn(3)-O(9) bond length is 1.87 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-61°. The As(1)-O(1) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.81 Å. The As(1)-O(5) bond length is 1.72 Å. The As(1)-O(7) bond length is 1.70 Å. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-58°. The As(2)-O(2) bond length is 1.72 Å. The As(2)-O(4) bond length is 1.82 Å. The As(2)-O(6) bond length is 1.72 Å. The As(2)-O(8) bond length is 1.69 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Mn(2) and one As(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(2) and one As(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(2), one Mn(3), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(2), one Mn(3), and one As(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(3) and one As(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Mn(3) and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mn(1) and one As(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one As(2) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Mn(2) and one Mn(3) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one Mn(2) and one Mn(3) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Mn(1) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Mn(1) 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) atom.