(MoO2)2P2O7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(4), one O(5), one O(9), and two equivalent O(2) atoms to form distorted MoO6 octahedra that share  a cornercorner with one Mo(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 27°. In the second Mo site, Mo(2) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(8) atoms to form distorted MoO6 octahedra that share  a cornercorner with one Mo(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 27°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Mo(2)O6 octahedra and corners with three equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-43°. In the second P site, P(2) is bonded to one O(5), one O(7), and two equivalent O(8) atoms to form PO4 tetrahedra that share  a cornercorner with one Mo(1)O6 octahedra and corners with three equivalent Mo(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mo(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mo(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Mo(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Mo(2) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Mo(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Mo(1) and one Mo(2) atom.
(MoO2)2P2O7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(1), one O(4), one O(5), one O(9), and two equivalent O(2) atoms to form distorted MoO6 octahedra that share  a cornercorner with one Mo(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 27°. The Mo(1)-O(1) bond length is 1.65 Å. The Mo(1)-O(4) bond length is 1.97 Å. The Mo(1)-O(5) bond length is 1.89 Å. The Mo(1)-O(9) bond length is 2.21 Å. Both Mo(1)-O(2) bond lengths are 1.95 Å. In the second Mo site, Mo(2) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(8) atoms to form distorted MoO6 octahedra that share  a cornercorner with one Mo(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with three equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 27°. The Mo(2)-O(3) bond length is 2.17 Å. The Mo(2)-O(6) bond length is 1.67 Å. The Mo(2)-O(7) bond length is 2.11 Å. The Mo(2)-O(9) bond length is 1.74 Å. Both Mo(2)-O(8) bond lengths are 1.98 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Mo(2)O6 octahedra and corners with three equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-43°. The P(1)-O(3) bond length is 1.49 Å. The P(1)-O(4) bond length is 1.55 Å. Both P(1)-O(2) bond lengths are 1.55 Å. In the second P site, P(2) is bonded to one O(5), one O(7), and two equivalent O(8) atoms to form PO4 tetrahedra that share  a cornercorner with one Mo(1)O6 octahedra and corners with three equivalent Mo(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(7) bond length is 1.50 Å. Both P(2)-O(8) bond lengths are 1.52 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mo(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mo(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Mo(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Mo(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Mo(2) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Mo(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Mo(1) and one Mo(2) atom.