Eu3O4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing EuO6 octahedra. The corner-sharing octahedral tilt angles range from 52-72°. In the second Eu site, Eu(2) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing EuO6 octahedra. The corner-sharing octahedral tilt angles range from 52-72°. In the third Eu site, Eu(3) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), two equivalent Eu(2), and two equivalent Eu(3) atoms to form a mixture of distorted corner and edge-sharing OEu5 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Eu(3) and three equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing OEu5 square pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Eu(2), one Eu(3), and two equivalent Eu(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Eu(3) and three equivalent Eu(2) atoms to form a mixture of distorted corner and edge-sharing OEu5 trigonal bipyramids.
Eu3O4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing EuO6 octahedra. The corner-sharing octahedral tilt angles range from 52-72°. The Eu(1)-O(1) bond length is 2.31 Å. Both Eu(1)-O(3) bond lengths are 2.27 Å. There is one shorter (2.44 Å) and two longer (2.50 Å) Eu(1)-O(2) bond lengths. In the second Eu site, Eu(2) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing EuO6 octahedra. The corner-sharing octahedral tilt angles range from 52-72°. The Eu(2)-O(3) bond length is 2.33 Å. Both Eu(2)-O(1) bond lengths are 2.49 Å. All Eu(2)-O(4) bond lengths are 2.42 Å. In the third Eu site, Eu(3) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Eu(3)-O(3) bond length is 2.49 Å. Both Eu(3)-O(1) bond lengths are 2.57 Å. Both Eu(3)-O(2) bond lengths are 2.56 Å. Both Eu(3)-O(4) bond lengths are 2.63 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), two equivalent Eu(2), and two equivalent Eu(3) atoms to form a mixture of distorted corner and edge-sharing OEu5 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Eu(3) and three equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing OEu5 square pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Eu(2), one Eu(3), and two equivalent Eu(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Eu(3) and three equivalent Eu(2) atoms to form a mixture of distorted corner and edge-sharing OEu5 trigonal bipyramids.