CaCoP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), and two equivalent O(2) atoms. Co(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) 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(2), one O(4), 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 46-57°. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), 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 31-46°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1), one P(1), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(2) 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. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Co(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(1) atom.
CaCoP2O7 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), and two equivalent O(2) atoms. The Ca(1)-O(1) bond length is 2.90 Å. The Ca(1)-O(3) bond length is 2.48 Å. The Ca(1)-O(5) bond length is 2.31 Å. The Ca(1)-O(6) bond length is 2.34 Å. The Ca(1)-O(7) bond length is 2.31 Å. There is one shorter (2.27 Å) and one longer (2.74 Å) Ca(1)-O(2) bond length. Co(1) is bonded to one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) 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(3) bond length is 2.17 Å. The Co(1)-O(5) bond length is 2.11 Å. The Co(1)-O(6) bond length is 2.14 Å. The Co(1)-O(7) bond length is 2.21 Å. There is one shorter (2.12 Å) and one longer (2.13 Å) Co(1)-O(4) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), 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 46-57°. The P(1)-O(1) bond length is 1.63 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.53 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(5), 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 31-46°. The P(2)-O(1) bond length is 1.63 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1), one P(1), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(2) 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. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Co(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Co(1), and one P(1) atom.