CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form CrO6 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(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-43°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-51°. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the second O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the sixth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom.
CrP2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Cr(1)-O(1) bond length is 1.95 Å. The Cr(1)-O(2) bond length is 2.01 Å. The Cr(1)-O(3) bond length is 1.90 Å. The Cr(1)-O(5) bond length is 1.94 Å. The Cr(1)-O(6) bond length is 1.90 Å. The Cr(1)-O(7) bond length is 1.96 Å. There are two inequivalent P sites. In the first P site, 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 three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-43°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.63 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 44-51°. The P(2)-O(4) bond length is 1.61 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.55 Å. The P(2)-O(7) bond length is 1.52 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the second O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the sixth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom.