Mn2P2O7 crystallizes in the monoclinic C2 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Mn(1)O6 octahedra. 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 three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-60°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom.
Mn2P2O7 crystallizes in the monoclinic C2 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Mn(2)O6 octahedra. Both Mn(1)-O(2) bond lengths are 2.29 Å. Both Mn(1)-O(3) bond lengths are 2.12 Å. Both Mn(1)-O(4) bond lengths are 2.16 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Mn(1)O6 octahedra. Both Mn(2)-O(2) bond lengths are 2.13 Å. Both Mn(2)-O(3) bond lengths are 2.30 Å. Both Mn(2)-O(4) bond lengths are 2.15 Å. 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 three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O6 octahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-60°. The P(1)-O(1) bond length is 1.58 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.52 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent P(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom.