U2CeS5 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to one S(1), one S(4), one S(5), two equivalent S(2), and two equivalent S(3) atoms to form distorted edge-sharing US7 pentagonal bipyramids. In the second U site, U(2) is bonded in a 8-coordinate geometry to one S(2), one S(3), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. Ce(1) is bonded in a 8-coordinate geometry to one S(2), one S(3), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. There are five inequivalent S sites. In the first S site, S(1) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form SCe2U3 square pyramids that share corners with four equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(3)CeU3 tetrahedra, corners with five equivalent S(5)Ce2U3 trigonal bipyramids, corners with four equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(4)Ce2U3 square pyramid, edges with two equivalent S(1)Ce2U3 square pyramids,  an edgeedge with one S(3)CeU3 tetrahedra, edges with two equivalent S(5)Ce2U3 trigonal bipyramids,  an edgeedge with one S(2)CeU3 trigonal pyramid, and  a faceface with one S(4)Ce2U3 square pyramid. In the second S site, S(2) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form distorted SCeU3 trigonal pyramids that share corners with two equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(1)Ce2U3 square pyramids, corners with four equivalent S(3)CeU3 tetrahedra, corners with two equivalent S(5)Ce2U3 trigonal bipyramids, corners with two equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(4)Ce2U3 square pyramids,  an edgeedge with one S(3)CeU3 tetrahedra, and edges with two equivalent S(5)Ce2U3 trigonal bipyramids. In the third S site, S(3) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form distorted SCeU3 tetrahedra that share corners with two equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(1)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra, corners with two equivalent S(5)Ce2U3 trigonal bipyramids, corners with four equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(4)Ce2U3 square pyramids, edges with two equivalent S(5)Ce2U3 trigonal bipyramids, and  an edgeedge with one S(2)CeU3 trigonal pyramid. In the fourth S site, S(4) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form distorted SCe2U3 square pyramids that share corners with four equivalent S(1)Ce2U3 square pyramids, corners with four equivalent S(4)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra,  a cornercorner with one S(5)Ce2U3 trigonal bipyramid, corners with two equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(3)CeU3 tetrahedra, edges with four equivalent S(5)Ce2U3 trigonal bipyramids, edges with two equivalent S(2)CeU3 trigonal pyramids, and  a faceface with one S(1)Ce2U3 square pyramid. In the fifth S site, S(5) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form distorted SCe2U3 trigonal bipyramids that share  a cornercorner with one S(4)Ce2U3 square pyramid, corners with five equivalent S(1)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra, corners with four equivalent S(5)Ce2U3 trigonal bipyramids, corners with two equivalent S(2)CeU3 trigonal pyramids, edges with two equivalent S(1)Ce2U3 square pyramids, edges with four equivalent S(4)Ce2U3 square pyramids, edges with two equivalent S(3)CeU3 tetrahedra, and edges with two equivalent S(2)CeU3 trigonal pyramids.
U2CeS5 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to one S(1), one S(4), one S(5), two equivalent S(2), and two equivalent S(3) atoms to form distorted edge-sharing US7 pentagonal bipyramids. The U(1)-S(1) bond length is 2.90 Å. The U(1)-S(4) bond length is 2.83 Å. The U(1)-S(5) bond length is 2.79 Å. There is one shorter (2.69 Å) and one longer (2.75 Å) U(1)-S(2) bond length. There is one shorter (2.66 Å) and one longer (2.76 Å) U(1)-S(3) bond length. In the second U site, U(2) is bonded in a 8-coordinate geometry to one S(2), one S(3), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. The U(2)-S(2) bond length is 2.85 Å. The U(2)-S(3) bond length is 2.87 Å. Both U(2)-S(1) bond lengths are 2.95 Å. There is one shorter (2.90 Å) and one longer (2.98 Å) U(2)-S(4) bond length. There is one shorter (2.96 Å) and one longer (3.10 Å) U(2)-S(5) bond length. Ce(1) is bonded in a 8-coordinate geometry to one S(2), one S(3), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. The Ce(1)-S(2) bond length is 2.94 Å. The Ce(1)-S(3) bond length is 2.93 Å. There is one shorter (2.94 Å) and one longer (2.96 Å) Ce(1)-S(1) bond length. Both Ce(1)-S(4) bond lengths are 2.94 Å. There is one shorter (2.98 Å) and one longer (3.07 Å) Ce(1)-S(5) bond length. There are five inequivalent S sites. In the first S site, S(1) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form SCe2U3 square pyramids that share corners with four equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(3)CeU3 tetrahedra, corners with five equivalent S(5)Ce2U3 trigonal bipyramids, corners with four equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(4)Ce2U3 square pyramid, edges with two equivalent S(1)Ce2U3 square pyramids,  an edgeedge with one S(3)CeU3 tetrahedra, edges with two equivalent S(5)Ce2U3 trigonal bipyramids,  an edgeedge with one S(2)CeU3 trigonal pyramid, and  a faceface with one S(4)Ce2U3 square pyramid. In the second S site, S(2) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form distorted SCeU3 trigonal pyramids that share corners with two equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(1)Ce2U3 square pyramids, corners with four equivalent S(3)CeU3 tetrahedra, corners with two equivalent S(5)Ce2U3 trigonal bipyramids, corners with two equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(4)Ce2U3 square pyramids,  an edgeedge with one S(3)CeU3 tetrahedra, and edges with two equivalent S(5)Ce2U3 trigonal bipyramids. In the third S site, S(3) is bonded to one U(2), two equivalent U(1), and one Ce(1) atom to form distorted SCeU3 tetrahedra that share corners with two equivalent S(4)Ce2U3 square pyramids, corners with four equivalent S(1)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra, corners with two equivalent S(5)Ce2U3 trigonal bipyramids, corners with four equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(4)Ce2U3 square pyramids, edges with two equivalent S(5)Ce2U3 trigonal bipyramids, and  an edgeedge with one S(2)CeU3 trigonal pyramid. In the fourth S site, S(4) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form distorted SCe2U3 square pyramids that share corners with four equivalent S(1)Ce2U3 square pyramids, corners with four equivalent S(4)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra,  a cornercorner with one S(5)Ce2U3 trigonal bipyramid, corners with two equivalent S(2)CeU3 trigonal pyramids,  an edgeedge with one S(1)Ce2U3 square pyramid, edges with two equivalent S(3)CeU3 tetrahedra, edges with four equivalent S(5)Ce2U3 trigonal bipyramids, edges with two equivalent S(2)CeU3 trigonal pyramids, and  a faceface with one S(1)Ce2U3 square pyramid. In the fifth S site, S(5) is bonded to one U(1), two equivalent U(2), and two equivalent Ce(1) atoms to form distorted SCe2U3 trigonal bipyramids that share  a cornercorner with one S(4)Ce2U3 square pyramid, corners with five equivalent S(1)Ce2U3 square pyramids, corners with two equivalent S(3)CeU3 tetrahedra, corners with four equivalent S(5)Ce2U3 trigonal bipyramids, corners with two equivalent S(2)CeU3 trigonal pyramids, edges with two equivalent S(1)Ce2U3 square pyramids, edges with four equivalent S(4)Ce2U3 square pyramids, edges with two equivalent S(3)CeU3 tetrahedra, and edges with two equivalent S(2)CeU3 trigonal pyramids.