MnP2O7 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Mn(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Mn(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 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 P(1) and one P(2) atom.
MnP2O7 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MnO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. The Mn(1)-O(2) bond length is 2.10 Å. The Mn(1)-O(3) bond length is 1.96 Å. The Mn(1)-O(4) bond length is 1.90 Å. The Mn(1)-O(5) bond length is 1.93 Å. The Mn(1)-O(6) bond length is 1.95 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Mn(1)O5 trigonal bipyramids. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.53 Å. The P(1)-O(7) bond length is 1.60 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Mn(1)O5 trigonal bipyramids. The P(2)-O(1) bond length is 1.53 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.59 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 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 P(1) and one P(2) atom.