LiCe2O3 crystallizes in the monoclinic Cm space group. Li(1) is bonded to one O(1), one O(2), and three equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Ce(2)O5 trigonal bipyramid, corners with six equivalent Li(1)O5 trigonal bipyramids, and edges with three equivalent Ce(2)O5 trigonal bipyramids. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 6-coordinate geometry to one O(1), three equivalent O(2), and three equivalent O(3) atoms. In the second Ce site, Ce(2) is bonded to one O(2), one O(3), and three equivalent O(1) atoms to form CeO5 trigonal bipyramids that share  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with six equivalent Ce(2)O5 trigonal bipyramids, and edges with three equivalent Li(1)O5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Ce(1), and three equivalent Ce(2) atoms to form a mixture of corner and edge-sharing OLiCe4 trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Ce(2), and three equivalent Ce(1) atoms to form a mixture of corner and edge-sharing OLiCe4 trigonal bipyramids. In the third O site, O(3) is bonded in a 7-coordinate geometry to three equivalent Li(1), one Ce(2), and three equivalent Ce(1) atoms.
LiCe2O3 crystallizes in the monoclinic Cm space group. Li(1) is bonded to one O(1), one O(2), and three equivalent O(3) atoms to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Ce(2)O5 trigonal bipyramid, corners with six equivalent Li(1)O5 trigonal bipyramids, and edges with three equivalent Ce(2)O5 trigonal bipyramids. The Li(1)-O(1) bond length is 2.12 Å. The Li(1)-O(2) bond length is 2.16 Å. There is one shorter (2.22 Å) and two longer (2.43 Å) Li(1)-O(3) bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 6-coordinate geometry to one O(1), three equivalent O(2), and three equivalent O(3) atoms. The Ce(1)-O(1) bond length is 2.61 Å. There is one shorter (2.32 Å) and two longer (2.37 Å) Ce(1)-O(2) bond lengths. There are two shorter (2.65 Å) and one longer (3.06 Å) Ce(1)-O(3) bond length. In the second Ce site, Ce(2) is bonded to one O(2), one O(3), and three equivalent O(1) atoms to form CeO5 trigonal bipyramids that share  a cornercorner with one Li(1)O5 trigonal bipyramid, corners with six equivalent Ce(2)O5 trigonal bipyramids, and edges with three equivalent Li(1)O5 trigonal bipyramids. The Ce(2)-O(2) bond length is 2.48 Å. The Ce(2)-O(3) bond length is 2.28 Å. There are two shorter (2.33 Å) and one longer (2.35 Å) Ce(2)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Ce(1), and three equivalent Ce(2) atoms to form a mixture of corner and edge-sharing OLiCe4 trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Ce(2), and three equivalent Ce(1) atoms to form a mixture of corner and edge-sharing OLiCe4 trigonal bipyramids. In the third O site, O(3) is bonded in a 7-coordinate geometry to three equivalent Li(1), one Ce(2), and three equivalent Ce(1) atoms.