CaCrP2O7 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms. Cr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(7), and two equivalent O(6) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form corner-sharing PO4 tetrahedra. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form corner-sharing PO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Cr(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(1), and one P(2) atom.
CaCrP2O7 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms. The Ca(1)-O(2) bond length is 2.39 Å. The Ca(1)-O(3) bond length is 2.35 Å. The Ca(1)-O(4) bond length is 2.51 Å. The Ca(1)-O(6) bond length is 2.64 Å. The Ca(1)-O(7) bond length is 2.77 Å. There is one shorter (2.31 Å) and one longer (2.41 Å) Ca(1)-O(5) bond length. Cr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(7), and two equivalent O(6) atoms. The Cr(1)-O(2) bond length is 2.09 Å. The Cr(1)-O(3) bond length is 2.49 Å. The Cr(1)-O(4) bond length is 2.15 Å. The Cr(1)-O(7) bond length is 2.10 Å. There is one shorter (2.11 Å) and one longer (2.69 Å) Cr(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(2), one O(5), and one O(6) atom to form corner-sharing PO4 tetrahedra. The P(1)-O(1) bond length is 1.60 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.52 Å. The P(1)-O(6) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form corner-sharing PO4 tetrahedra. 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(4) bond length is 1.55 Å. The P(2)-O(7) bond length is 1.53 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Cr(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(1), one Cr(1), and one P(2) atom.