Cs2CeO3 crystallizes in the triclinic P1 space group. There are eight inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), one O(7), one O(9), and two equivalent O(8) atoms. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(8), and two equivalent O(9) atoms. In the third Cs site, Cs(3) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(6), and two equivalent O(11) atoms. In the fourth Cs site, Cs(4) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(5), and two equivalent O(10) atoms. In the fifth Cs site, Cs(5) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(9), and two equivalent O(3) atoms. In the sixth Cs site, Cs(6) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), and two equivalent O(2) atoms. In the seventh Cs site, Cs(7) is bonded in a 5-coordinate geometry to one O(10), one O(4), one O(8), and two equivalent O(5) atoms. In the eighth Cs site, Cs(8) is bonded in a 7-coordinate geometry to one O(12), one O(5), one O(6), one O(8), one O(9), and two equivalent O(4) atoms. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form corner-sharing CeO4 tetrahedra. In the second Ce site, Ce(2) is bonded to one O(12), one O(4), one O(5), and one O(6) atom to form corner-sharing CeO4 tetrahedra. In the third Ce site, Ce(3) is bonded to one O(10), one O(11), one O(12), and one O(6) atom to form corner-sharing CeO4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one O(1), one O(7), one O(8), and one O(9) atom to form corner-sharing CeO4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(6), one Ce(1), and one Ce(4) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Cs(3), one Cs(4), one Cs(5), two equivalent Cs(6), and one Ce(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Cs(2), one Cs(3), one Cs(6), two equivalent Cs(5), and one Ce(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(2), one Cs(7), two equivalent Cs(8), and one Ce(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(4), one Cs(8), two equivalent Cs(7), and one Ce(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(3), one Cs(8), one Ce(2), and one Ce(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(6), one Ce(1), and one Ce(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Cs(2), one Cs(7), one Cs(8), two equivalent Cs(1), and one Ce(4) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(5), one Cs(8), two equivalent Cs(2), and one Ce(4) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Cs(3), one Cs(6), one Cs(7), two equivalent Cs(4), and one Ce(3) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Cs(4), one Cs(5), one Cs(6), two equivalent Cs(3), and one Ce(3) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Cs(3), one Cs(8), one Ce(2), and one Ce(3) atom.
Cs2CeO3 crystallizes in the triclinic P1 space group. There are eight inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(5), one O(7), one O(9), and two equivalent O(8) atoms. The Cs(1)-O(1) bond length is 3.28 Å. The Cs(1)-O(4) bond length is 3.43 Å. The Cs(1)-O(5) bond length is 3.18 Å. The Cs(1)-O(7) bond length is 3.29 Å. The Cs(1)-O(9) bond length is 2.98 Å. There is one shorter (3.47 Å) and one longer (3.52 Å) Cs(1)-O(8) bond length. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(8), and two equivalent O(9) atoms. The Cs(2)-O(3) bond length is 3.48 Å. The Cs(2)-O(4) bond length is 3.06 Å. The Cs(2)-O(8) bond length is 3.06 Å. There is one shorter (3.43 Å) and one longer (3.52 Å) Cs(2)-O(9) bond length. In the third Cs site, Cs(3) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(6), and two equivalent O(11) atoms. The Cs(3)-O(10) bond length is 2.94 Å. The Cs(3)-O(12) bond length is 3.25 Å. The Cs(3)-O(2) bond length is 3.51 Å. The Cs(3)-O(3) bond length is 3.19 Å. The Cs(3)-O(6) bond length is 3.27 Å. There is one shorter (3.51 Å) and one longer (3.52 Å) Cs(3)-O(11) bond length. In the fourth Cs site, Cs(4) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(5), and two equivalent O(10) atoms. The Cs(4)-O(11) bond length is 3.10 Å. The Cs(4)-O(2) bond length is 3.06 Å. The Cs(4)-O(5) bond length is 3.48 Å. There is one shorter (3.43 Å) and one longer (3.52 Å) Cs(4)-O(10) bond length. In the fifth Cs site, Cs(5) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(9), and two equivalent O(3) atoms. The Cs(5)-O(11) bond length is 3.13 Å. The Cs(5)-O(2) bond length is 3.04 Å. The Cs(5)-O(9) bond length is 3.43 Å. There is one shorter (3.42 Å) and one longer (3.54 Å) Cs(5)-O(3) bond length. In the sixth Cs site, Cs(6) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), and two equivalent O(2) atoms. The Cs(6)-O(1) bond length is 3.25 Å. The Cs(6)-O(10) bond length is 3.20 Å. The Cs(6)-O(11) bond length is 3.45 Å. The Cs(6)-O(3) bond length is 2.94 Å. The Cs(6)-O(7) bond length is 3.32 Å. There is one shorter (3.46 Å) and one longer (3.54 Å) Cs(6)-O(2) bond length. In the seventh Cs site, Cs(7) is bonded in a 5-coordinate geometry to one O(10), one O(4), one O(8), and two equivalent O(5) atoms. The Cs(7)-O(10) bond length is 3.44 Å. The Cs(7)-O(4) bond length is 3.10 Å. The Cs(7)-O(8) bond length is 3.09 Å. There is one shorter (3.47 Å) and one longer (3.48 Å) Cs(7)-O(5) bond length. In the eighth Cs site, Cs(8) is bonded in a 7-coordinate geometry to one O(12), one O(5), one O(6), one O(8), one O(9), and two equivalent O(4) atoms. The Cs(8)-O(12) bond length is 3.35 Å. The Cs(8)-O(5) bond length is 2.94 Å. The Cs(8)-O(6) bond length is 3.28 Å. The Cs(8)-O(8) bond length is 3.50 Å. The Cs(8)-O(9) bond length is 3.15 Å. There is one shorter (3.50 Å) and one longer (3.51 Å) Cs(8)-O(4) bond length. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form corner-sharing CeO4 tetrahedra. The Ce(1)-O(1) bond length is 2.21 Å. The Ce(1)-O(2) bond length is 2.05 Å. The Ce(1)-O(3) bond length is 2.04 Å. The Ce(1)-O(7) bond length is 2.21 Å. In the second Ce site, Ce(2) is bonded to one O(12), one O(4), one O(5), and one O(6) atom to form corner-sharing CeO4 tetrahedra. The Ce(2)-O(12) bond length is 2.21 Å. The Ce(2)-O(4) bond length is 2.05 Å. The Ce(2)-O(5) bond length is 2.04 Å. The Ce(2)-O(6) bond length is 2.21 Å. In the third Ce site, Ce(3) is bonded to one O(10), one O(11), one O(12), and one O(6) atom to form corner-sharing CeO4 tetrahedra. The Ce(3)-O(10) bond length is 2.04 Å. The Ce(3)-O(11) bond length is 2.04 Å. The Ce(3)-O(12) bond length is 2.21 Å. The Ce(3)-O(6) bond length is 2.21 Å. In the fourth Ce site, Ce(4) is bonded to one O(1), one O(7), one O(8), and one O(9) atom to form corner-sharing CeO4 tetrahedra. The Ce(4)-O(1) bond length is 2.21 Å. The Ce(4)-O(7) bond length is 2.21 Å. The Ce(4)-O(8) bond length is 2.05 Å. The Ce(4)-O(9) bond length is 2.04 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(6), one Ce(1), and one Ce(4) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Cs(3), one Cs(4), one Cs(5), two equivalent Cs(6), and one Ce(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Cs(2), one Cs(3), one Cs(6), two equivalent Cs(5), and one Ce(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(2), one Cs(7), two equivalent Cs(8), and one Ce(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(4), one Cs(8), two equivalent Cs(7), and one Ce(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(3), one Cs(8), one Ce(2), and one Ce(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(6), one Ce(1), and one Ce(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Cs(2), one Cs(7), one Cs(8), two equivalent Cs(1), and one Ce(4) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Cs(1), one Cs(5), one Cs(8), two equivalent Cs(2), and one Ce(4) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Cs(3), one Cs(6), one Cs(7), two equivalent Cs(4), and one Ce(3) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Cs(4), one Cs(5), one Cs(6), two equivalent Cs(3), and one Ce(3) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Cs(3), one Cs(8), one Ce(2), and one Ce(3) atom.