BaCr2(P2O7)2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), 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(3), 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(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) 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 30-51°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Cr(1), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(1) atom.
BaCr2(P2O7)2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms. Both Ba(1)-O(1) bond lengths are 3.13 Å. Both Ba(1)-O(2) bond lengths are 2.80 Å. Both Ba(1)-O(3) bond lengths are 3.01 Å. Both Ba(1)-O(4) bond lengths are 2.86 Å. Both Ba(1)-O(7) bond lengths are 2.99 Å. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), 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 2.00 Å. The Cr(1)-O(2) bond length is 2.01 Å. The Cr(1)-O(3) bond length is 2.01 Å. The Cr(1)-O(4) bond length is 2.01 Å. The Cr(1)-O(5) bond length is 1.98 Å. The Cr(1)-O(7) bond length is 2.05 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), 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(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-51°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.62 Å. The P(1)-O(7) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(2), one O(4), one O(5), and one O(6) 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 30-51°. The P(2)-O(2) bond length is 1.55 Å. The P(2)-O(4) bond length is 1.54 Å. The P(2)-O(5) bond length is 1.50 Å. The P(2)-O(6) bond length is 1.62 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 Ba(1), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Cr(1), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ba(1), one Cr(1), and one P(1) atom.