CoP2O7 crystallizes in the monoclinic P2_1 space group. Co(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-45°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-43°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom.
CoP2O7 crystallizes in the monoclinic P2_1 space group. Co(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Co(1)-O(1) bond length is 1.98 Å. The Co(1)-O(3) bond length is 2.04 Å. The Co(1)-O(4) bond length is 2.00 Å. The Co(1)-O(5) bond length is 1.94 Å. The Co(1)-O(6) bond length is 1.97 Å. The Co(1)-O(7) bond length is 2.00 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-45°. The P(1)-O(2) bond length is 1.62 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(6) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.51 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-43°. The P(2)-O(1) bond length is 1.52 Å. The P(2)-O(2) bond length is 1.62 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom.