Ca2Fe2O5 crystallizes in the orthorhombic Pbam space group. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing FeO5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ca(1) and two equivalent Fe(1) atoms to form OCa4Fe2 octahedra that share corners with eight equivalent O(2)Ca2Fe2 tetrahedra, edges with two equivalent O(1)Ca4Fe2 octahedra, and edges with two equivalent O(2)Ca2Fe2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form distorted OCa2Fe2 tetrahedra that share corners with four equivalent O(1)Ca4Fe2 octahedra, corners with four equivalent O(2)Ca2Fe2 tetrahedra, and  an edgeedge with one O(1)Ca4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 8-72°. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Fe(1) atoms.
Ca2Fe2O5 crystallizes in the orthorhombic Pbam space group. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Ca(1)-O(1) bond lengths are 2.61 Å. Both Ca(1)-O(2) bond lengths are 2.36 Å. There are a spread of Ca(1)-O(3) bond distances ranging from 2.37-2.91 Å. Fe(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing FeO5 square pyramids. The Fe(1)-O(1) bond length is 2.02 Å. There is one shorter (1.91 Å) and one longer (2.00 Å) Fe(1)-O(2) bond length. Both Fe(1)-O(3) bond lengths are 2.00 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ca(1) and two equivalent Fe(1) atoms to form OCa4Fe2 octahedra that share corners with eight equivalent O(2)Ca2Fe2 tetrahedra, edges with two equivalent O(1)Ca4Fe2 octahedra, and edges with two equivalent O(2)Ca2Fe2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form distorted OCa2Fe2 tetrahedra that share corners with four equivalent O(1)Ca4Fe2 octahedra, corners with four equivalent O(2)Ca2Fe2 tetrahedra, and  an edgeedge with one O(1)Ca4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 8-72°. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Fe(1) atoms.