SrEuAlO4 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4mm space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. Eu(1) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(3) atoms. Al(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Eu(1), and one Al(1) atom to form distorted OSrEu4Al octahedra that share  a cornercorner with one O(2)Sr4EuAl octahedra, corners with four equivalent O(1)SrEu4Al octahedra, corners with twelve equivalent O(3)Sr2Eu2Al2 octahedra, edges with four equivalent O(2)Sr4EuAl octahedra, edges with four equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-54°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Eu(1), and one Al(1) atom to form distorted OSr4EuAl octahedra that share  a cornercorner with one O(1)SrEu4Al octahedra, corners with four equivalent O(2)Sr4EuAl octahedra, corners with twelve equivalent O(3)Sr2Eu2Al2 octahedra, edges with four equivalent O(2)Sr4EuAl octahedra, edges with four equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-56°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Al(1) atoms to form distorted OSr2Eu2Al2 octahedra that share corners with two equivalent O(3)Sr2Eu2Al2 octahedra, corners with six equivalent O(2)Sr4EuAl octahedra, corners with six equivalent O(1)SrEu4Al octahedra, edges with two equivalent O(3)Sr2Eu2Al2 octahedra, faces with two equivalent O(2)Sr4EuAl octahedra, faces with two equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 5-56°.
SrEuAlO4 is (La,Ba)CuO4-derived structured and crystallizes in the tetragonal I4mm space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), four equivalent O(2), and four equivalent O(3) atoms. The Sr(1)-O(1) bond length is 2.43 Å. All Sr(1)-O(2) bond lengths are 2.67 Å. All Sr(1)-O(3) bond lengths are 2.64 Å. Eu(1) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(3) atoms. The Eu(1)-O(2) bond length is 2.42 Å. All Eu(1)-O(1) bond lengths are 2.67 Å. All Eu(1)-O(3) bond lengths are 2.52 Å. Al(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 5°. The Al(1)-O(1) bond length is 1.99 Å. The Al(1)-O(2) bond length is 2.02 Å. All Al(1)-O(3) bond lengths are 1.88 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Eu(1), and one Al(1) atom to form distorted OSrEu4Al octahedra that share  a cornercorner with one O(2)Sr4EuAl octahedra, corners with four equivalent O(1)SrEu4Al octahedra, corners with twelve equivalent O(3)Sr2Eu2Al2 octahedra, edges with four equivalent O(2)Sr4EuAl octahedra, edges with four equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-54°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Eu(1), and one Al(1) atom to form distorted OSr4EuAl octahedra that share  a cornercorner with one O(1)SrEu4Al octahedra, corners with four equivalent O(2)Sr4EuAl octahedra, corners with twelve equivalent O(3)Sr2Eu2Al2 octahedra, edges with four equivalent O(2)Sr4EuAl octahedra, edges with four equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-56°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Al(1) atoms to form distorted OSr2Eu2Al2 octahedra that share corners with two equivalent O(3)Sr2Eu2Al2 octahedra, corners with six equivalent O(2)Sr4EuAl octahedra, corners with six equivalent O(1)SrEu4Al octahedra, edges with two equivalent O(3)Sr2Eu2Al2 octahedra, faces with two equivalent O(2)Sr4EuAl octahedra, faces with two equivalent O(1)SrEu4Al octahedra, and faces with four equivalent O(3)Sr2Eu2Al2 octahedra. The corner-sharing octahedral tilt angles range from 5-56°.