Eu3AlO5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a distorted q6 geometry to two equivalent O(1) and eight equivalent O(2) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(2) atoms. Al(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1) and four equivalent Eu(2) atoms to form corner-sharing OEu6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Eu(1), three equivalent Eu(2), and one Al(1) atom.
Eu3AlO5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a distorted q6 geometry to two equivalent O(1) and eight equivalent O(2) atoms. Both Eu(1)-O(1) bond lengths are 2.78 Å. All Eu(1)-O(2) bond lengths are 2.81 Å. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(2) atoms. Both Eu(2)-O(1) bond lengths are 2.47 Å. There are two shorter (2.37 Å) and four longer (2.73 Å) Eu(2)-O(2) bond lengths. Al(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. All Al(1)-O(2) bond lengths are 1.77 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1) and four equivalent Eu(2) atoms to form corner-sharing OEu6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Eu(1), three equivalent Eu(2), and one Al(1) atom.