Ca3Mn2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to three equivalent O(4) and four equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Mn(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 19-26°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ca(2) and one Mn(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Mn(1) atoms.
Ca3Mn2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to three equivalent O(4) and four equivalent O(2) atoms. There is one shorter (2.32 Å) and two longer (2.71 Å) Ca(1)-O(4) bond lengths. All Ca(1)-O(2) bond lengths are 2.45 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Both Ca(2)-O(2) bond lengths are 2.74 Å. Both Ca(2)-O(3) bond lengths are 2.38 Å. There are a spread of Ca(2)-O(1) bond distances ranging from 2.29-2.69 Å. Mn(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 19-26°. The Mn(1)-O(1) bond length is 1.92 Å. The Mn(1)-O(4) bond length is 1.95 Å. Both Mn(1)-O(2) bond lengths are 1.94 Å. Both Mn(1)-O(3) bond lengths are 1.93 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Ca(2) and one Mn(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Mn(1) atoms.