SrEu4O5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/m space group. Sr(1) is bonded to two equivalent O(1) and four O(2,2) atoms to form SrO6 octahedra that share corners with two equivalent Sr(1)O6 octahedra, corners with four equivalent Eu(1)O6 octahedra, and edges with twelve equivalent Eu(1)O6 octahedra. The corner-sharing octahedra are not tilted. Eu(1) is bonded to one O(1) and five O(2,2) atoms to form EuO6 octahedra that share  a cornercorner with one Sr(1)O6 octahedra, corners with five equivalent Eu(1)O6 octahedra, edges with three equivalent Sr(1)O6 octahedra, and edges with nine equivalent Eu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and four equivalent Eu(1) atoms to form OSr2Eu4 octahedra that share corners with two equivalent O(1)Sr2Eu4 octahedra; corners with four O(2,2,2)SrEu5 octahedra; and edges with twelve O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.
SrEu4O5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/m space group. Sr(1) is bonded to two equivalent O(1) and four O(2,2) atoms to form SrO6 octahedra that share corners with two equivalent Sr(1)O6 octahedra, corners with four equivalent Eu(1)O6 octahedra, and edges with twelve equivalent Eu(1)O6 octahedra. The corner-sharing octahedra are not tilted. Both Sr(1)-O(1) bond lengths are 2.54 Å. All Sr(1)-O(2,2) bond lengths are 2.57 Å. Eu(1) is bonded to one O(1) and five O(2,2) atoms to form EuO6 octahedra that share  a cornercorner with one Sr(1)O6 octahedra, corners with five equivalent Eu(1)O6 octahedra, edges with three equivalent Sr(1)O6 octahedra, and edges with nine equivalent Eu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Eu(1)-O(1) bond length is 2.55 Å. There is one shorter (2.51 Å) and four longer (2.54 Å) Eu(1)-O(2,2) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and four equivalent Eu(1) atoms to form OSr2Eu4 octahedra that share corners with two equivalent O(1)Sr2Eu4 octahedra; corners with four O(2,2,2)SrEu5 octahedra; and edges with twelve O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fourth O site, O(2) is bonded to one Sr(1) and five equivalent Eu(1) atoms to form OSrEu5 octahedra that share  a cornercorner with one O(1)Sr2Eu4 octahedra; corners with five O(2,2,2)SrEu5 octahedra; edges with three equivalent O(1)Sr2Eu4 octahedra; and edges with nine O(2,2)SrEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. The O(2)-Sr(1) bond length is 2.57 Å. There is one shorter (2.51 Å) and four longer (2.54 Å) O(2)-Eu(1) bond lengths.