CaCr2O6 crystallizes in the triclinic P1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(3), one O(6), one O(7), and one O(8) atom. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. In the second Cr site, Cr(2) is bonded to one O(1), one O(10), one O(4), one O(7), one O(8), and one O(9) atom to form distorted corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. In the third Cr site, Cr(3) is bonded to one O(1), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(2), one O(3), one O(5), and one O(6) atom to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 13-29°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(2), and one Cr(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cr(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(1), and one Cr(4) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one Cr(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(3), and one Cr(4) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(3), and one Cr(4) atom. In the seventh O site, O(7) is bonded in a 1-coordinate geometry to one Ca(1), one Ca(2), one Cr(1), and one Cr(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Cr(1), and one Cr(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cr(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(1), and one Cr(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Cr(3), and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a distorted square co-planar geometry to one Ca(1), one Ca(2), one Cr(3), and one Cr(4) atom.
CaCr2O6 crystallizes in the triclinic P1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(11), one O(12), one O(2), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. The Ca(1)-O(11) bond length is 2.50 Å. The Ca(1)-O(12) bond length is 2.44 Å. The Ca(1)-O(2) bond length is 2.46 Å. The Ca(1)-O(4) bond length is 2.49 Å. The Ca(1)-O(5) bond length is 2.31 Å. The Ca(1)-O(7) bond length is 2.56 Å. The Ca(1)-O(8) bond length is 2.67 Å. The Ca(1)-O(9) bond length is 2.43 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(3), one O(6), one O(7), and one O(8) atom. The Ca(2)-O(1) bond length is 2.43 Å. The Ca(2)-O(10) bond length is 2.38 Å. The Ca(2)-O(11) bond length is 2.45 Å. The Ca(2)-O(12) bond length is 2.55 Å. The Ca(2)-O(3) bond length is 2.51 Å. The Ca(2)-O(6) bond length is 2.32 Å. The Ca(2)-O(7) bond length is 2.66 Å. The Ca(2)-O(8) bond length is 2.50 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. The Cr(1)-O(10) bond length is 2.17 Å. The Cr(1)-O(2) bond length is 1.75 Å. The Cr(1)-O(3) bond length is 1.78 Å. The Cr(1)-O(7) bond length is 1.68 Å. The Cr(1)-O(8) bond length is 2.29 Å. The Cr(1)-O(9) bond length is 1.68 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(10), one O(4), one O(7), one O(8), and one O(9) atom to form distorted corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. The Cr(2)-O(1) bond length is 1.86 Å. The Cr(2)-O(10) bond length is 1.69 Å. The Cr(2)-O(4) bond length is 1.90 Å. The Cr(2)-O(7) bond length is 2.22 Å. The Cr(2)-O(8) bond length is 1.71 Å. The Cr(2)-O(9) bond length is 2.11 Å. In the third Cr site, Cr(3) is bonded to one O(1), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 4-32°. The Cr(3)-O(1) bond length is 1.90 Å. The Cr(3)-O(11) bond length is 1.79 Å. The Cr(3)-O(12) bond length is 2.09 Å. The Cr(3)-O(4) bond length is 1.86 Å. The Cr(3)-O(5) bond length is 2.06 Å. The Cr(3)-O(6) bond length is 1.80 Å. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(2), one O(3), one O(5), and one O(6) atom to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 13-29°. The Cr(4)-O(11) bond length is 2.11 Å. The Cr(4)-O(12) bond length is 1.83 Å. The Cr(4)-O(2) bond length is 2.05 Å. The Cr(4)-O(3) bond length is 1.96 Å. The Cr(4)-O(5) bond length is 1.79 Å. The Cr(4)-O(6) bond length is 1.98 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(2), and one Cr(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cr(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(1), and one Cr(4) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(2), and one Cr(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(3), and one Cr(4) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(3), and one Cr(4) atom. In the seventh O site, O(7) is bonded in a 1-coordinate geometry to one Ca(1), one Ca(2), one Cr(1), and one Cr(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Cr(1), and one Cr(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Cr(1), and one Cr(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(2), one Cr(1), and one Cr(2) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Cr(3), and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a distorted square co-planar geometry to one Ca(1), one Ca(2), one Cr(3), and one Cr(4) atom.