Ce5O9 crystallizes in the monoclinic C2 space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. In the second Ce site, Ce(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms. In the third Ce site, Ce(3) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ce(1) and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the second O site, O(2) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the third O site, O(3) is bonded to one Ce(1), one Ce(3), and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the fourth O site, O(4) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form a mixture of distorted edge and corner-sharing OCe4 tetrahedra. In the fifth O site, O(5) is bonded to one Ce(1), one Ce(3), and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra.
Ce5O9 crystallizes in the monoclinic C2 space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. The Ce(1)-O(1) bond length is 2.42 Å. The Ce(1)-O(3) bond length is 2.29 Å. The Ce(1)-O(5) bond length is 2.39 Å. There is one shorter (2.38 Å) and one longer (2.41 Å) Ce(1)-O(2) bond length. There is one shorter (2.27 Å) and one longer (2.35 Å) Ce(1)-O(4) bond length. In the second Ce site, Ce(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms. The Ce(2)-O(1) bond length is 2.42 Å. The Ce(2)-O(2) bond length is 2.28 Å. The Ce(2)-O(4) bond length is 2.39 Å. There is one shorter (2.38 Å) and one longer (2.41 Å) Ce(2)-O(3) bond length. There is one shorter (2.28 Å) and one longer (2.35 Å) Ce(2)-O(5) bond length. In the third Ce site, Ce(3) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Both Ce(3)-O(2) bond lengths are 2.30 Å. Both Ce(3)-O(3) bond lengths are 2.30 Å. Both Ce(3)-O(4) bond lengths are 2.59 Å. Both Ce(3)-O(5) bond lengths are 2.58 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ce(1) and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the second O site, O(2) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the third O site, O(3) is bonded to one Ce(1), one Ce(3), and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the fourth O site, O(4) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form a mixture of distorted edge and corner-sharing OCe4 tetrahedra. In the fifth O site, O(5) is bonded to one Ce(1), one Ce(3), and two equivalent Ce(2) atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra.