CrP2O7 crystallizes in the triclinic P-1 space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)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(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. 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  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom.
CrP2O7 crystallizes in the triclinic P-1 space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form CrO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. The Cr(1)-O(1) bond length is 1.97 Å. The Cr(1)-O(2) bond length is 1.90 Å. The Cr(1)-O(3) bond length is 1.89 Å. The Cr(1)-O(5) bond length is 1.83 Å. The Cr(1)-O(7) bond length is 1.94 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(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cr(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.57 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  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. The P(2)-O(4) bond length is 1.49 Å. The P(2)-O(5) bond length is 1.58 Å. The P(2)-O(6) bond length is 1.60 Å. The P(2)-O(7) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one P(2) atom.