Eu2Fe2O5 crystallizes in the orthorhombic Ima2 space group. Eu(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 14°. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Eu(1) and two equivalent Fe(1) atoms to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with four equivalent O(3)Eu2Fe2 tetrahedra, edges with two equivalent O(1)Eu4Fe2 octahedra, and faces with four equivalent O(1)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Eu(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded to two equivalent Eu(1) and two equivalent Fe(2) atoms to form OEu2Fe2 tetrahedra that share corners with eight equivalent O(1)Eu4Fe2 octahedra and corners with two equivalent O(3)Eu2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 23-75°.
Eu2Fe2O5 crystallizes in the orthorhombic Ima2 space group. Eu(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. The Eu(1)-O(3) bond length is 2.31 Å. There are a spread of Eu(1)-O(2) bond distances ranging from 2.40-2.96 Å. There are two shorter (2.56 Å) and two longer (2.75 Å) Eu(1)-O(1) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 14°. Both Fe(1)-O(2) bond lengths are 2.10 Å. There are two shorter (1.98 Å) and two longer (2.01 Å) Fe(1)-O(1) bond lengths. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. Both Fe(2)-O(2) bond lengths are 1.98 Å. There is one shorter (2.09 Å) and one longer (2.11 Å) Fe(2)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Eu(1) and two equivalent Fe(1) atoms to form distorted OEu4Fe2 octahedra that share corners with two equivalent O(1)Eu4Fe2 octahedra, corners with four equivalent O(3)Eu2Fe2 tetrahedra, edges with two equivalent O(1)Eu4Fe2 octahedra, and faces with four equivalent O(1)Eu4Fe2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Eu(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded to two equivalent Eu(1) and two equivalent Fe(2) atoms to form OEu2Fe2 tetrahedra that share corners with eight equivalent O(1)Eu4Fe2 octahedra and corners with two equivalent O(3)Eu2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 23-75°.