Ca2Mn2O5 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. Mn(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing MnO5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Mn2 trigonal pyramids. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms to form distorted corner-sharing OCa2Mn2 trigonal pyramids.
Ca2Mn2O5 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Ca(1)-O(3) bond length is 2.39 Å. Both Ca(1)-O(1) bond lengths are 2.40 Å. Both Ca(1)-O(2) bond lengths are 2.36 Å. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Ca(2)-O(3) bond length is 2.23 Å. Both Ca(2)-O(1) bond lengths are 2.30 Å. Both Ca(2)-O(2) bond lengths are 2.40 Å. Mn(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing MnO5 square pyramids. The Mn(1)-O(3) bond length is 2.02 Å. There is one shorter (1.96 Å) and one longer (2.01 Å) Mn(1)-O(1) bond length. There is one shorter (1.97 Å) and one longer (1.99 Å) Mn(1)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Mn2 trigonal pyramids. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), and two equivalent Mn(1) atoms to form distorted corner-sharing OCa2Mn2 trigonal pyramids.