Ca2FeAlO5 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(3), and four equivalent O(2) atoms. Fe(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 32°. Al(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with four equivalent Al(1)O6 octahedra and corners with two equivalent Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 10°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form distorted OCa2Fe2 tetrahedra that share corners with eight equivalent O(2)Ca4Al2 octahedra and corners with two equivalent O(1)Ca2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 25-76°. In the second O site, O(2) is bonded to four equivalent Ca(1) and two equivalent Al(1) atoms to form distorted OCa4Al2 octahedra that share corners with two equivalent O(2)Ca4Al2 octahedra, corners with four equivalent O(1)Ca2Fe2 tetrahedra, edges with two equivalent O(2)Ca4Al2 octahedra, and faces with four equivalent O(2)Ca4Al2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Fe(1), and one Al(1) atom.
Ca2FeAlO5 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(3), and four equivalent O(2) atoms. The Ca(1)-O(1) bond length is 2.33 Å. There are a spread of Ca(1)-O(3) bond distances ranging from 2.35-2.82 Å. There are a spread of Ca(1)-O(2) bond distances ranging from 2.42-2.57 Å. Fe(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and corners with two equivalent Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 32°. There is one shorter (1.94 Å) and one longer (1.96 Å) Fe(1)-O(1) bond length. Both Fe(1)-O(3) bond lengths are 1.88 Å. Al(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with four equivalent Al(1)O6 octahedra and corners with two equivalent Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 10°. Both Al(1)-O(3) bond lengths are 2.06 Å. All Al(1)-O(2) bond lengths are 1.91 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form distorted OCa2Fe2 tetrahedra that share corners with eight equivalent O(2)Ca4Al2 octahedra and corners with two equivalent O(1)Ca2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 25-76°. In the second O site, O(2) is bonded to four equivalent Ca(1) and two equivalent Al(1) atoms to form distorted OCa4Al2 octahedra that share corners with two equivalent O(2)Ca4Al2 octahedra, corners with four equivalent O(1)Ca2Fe2 tetrahedra, edges with two equivalent O(2)Ca4Al2 octahedra, and faces with four equivalent O(2)Ca4Al2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Fe(1), and one Al(1) atom.