Co2P2O7 crystallizes in the triclinic P-1 space group. Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted CoO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Co(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 six equivalent Co(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-62°. 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 3-coordinate geometry to two equivalent Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom.
Co2P2O7 crystallizes in the triclinic P-1 space group. Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted CoO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with three equivalent Co(1)O6 octahedra. There is one shorter (2.02 Å) and one longer (2.27 Å) Co(1)-O(2) bond length. There is one shorter (2.09 Å) and one longer (2.21 Å) Co(1)-O(3) bond length. There is one shorter (2.06 Å) and one longer (2.07 Å) Co(1)-O(4) bond length. 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 six equivalent Co(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-62°. The P(1)-O(1) bond length is 1.56 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 3-coordinate geometry to two equivalent Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom.