CoP2O7 crystallizes in the triclinic P-1 space group. Co(1) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent O(6) atoms to form CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Co(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), 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 36-47°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(6) 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 28-54°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to 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(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom.
CoP2O7 crystallizes in the triclinic P-1 space group. Co(1) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent O(6) atoms to form CoO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Co(1)O6 octahedra. The Co(1)-O(1) bond length is 1.89 Å. The Co(1)-O(3) bond length is 2.04 Å. The Co(1)-O(5) bond length is 1.87 Å. The Co(1)-O(7) bond length is 2.00 Å. There is one shorter (2.14 Å) and one longer (2.17 Å) Co(1)-O(6) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), 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 36-47°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.61 Å. The P(1)-O(5) bond length is 1.53 Å. The P(1)-O(7) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(2), one O(3), one O(4), and one O(6) 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 28-54°. The P(2)-O(2) bond length is 1.53 Å. The P(2)-O(3) bond length is 1.51 Å. The P(2)-O(4) bond length is 1.60 Å. The P(2)-O(6) bond length is 1.55 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to 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(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom.