Ca3Cr2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(3), and three equivalent O(2) atoms. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 21-25°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Cr(1) atoms.
Ca3Cr2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. There is one shorter (2.39 Å) and one longer (2.45 Å) Ca(1)-O(1) bond length. Both Ca(1)-O(3) bond lengths are 2.60 Å. There are two shorter (2.38 Å) and two longer (2.61 Å) Ca(1)-O(4) bond lengths. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(3), and three equivalent O(2) atoms. The Ca(2)-O(4) bond length is 2.44 Å. There is one shorter (2.30 Å) and one longer (2.57 Å) Ca(2)-O(3) bond length. There are a spread of Ca(2)-O(2) bond distances ranging from 2.32-2.45 Å. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 21-25°. The Cr(1)-O(1) bond length is 1.94 Å. The Cr(1)-O(2) bond length is 1.91 Å. There is one shorter (1.91 Å) and one longer (1.99 Å) Cr(1)-O(3) bond length. There is one shorter (1.92 Å) and one longer (2.00 Å) Cr(1)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Cr(1) atoms.