Yb16S29 crystallizes in the tetragonal I-42m space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 9-coordinate geometry to one S(1), one S(3), one S(7), two equivalent S(4), two equivalent S(5), and two equivalent S(6) atoms. In the second Yb site, Yb(2) is bonded in a 8-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(6), and three equivalent S(5) atoms. In the third Yb site, Yb(3) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(2), two equivalent S(3), and two equivalent S(5) atoms. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(3), two equivalent Yb(2), two equivalent S(2), and two equivalent S(4) atoms. In the second S site, S(2) is bonded in a distorted hexagonal planar geometry to two equivalent Yb(2), two equivalent Yb(3), and two equivalent S(1) atoms. In the third S site, S(3) is bonded to one Yb(1), two equivalent Yb(2), and two equivalent Yb(3) atoms to form distorted SYb5 trigonal bipyramids that share  a cornercorner with one S(7)Yb4S4 hexagonal bipyramid, corners with four equivalent S(5)Yb5 trigonal bipyramids,  an edgeedge with one S(3)Yb5 trigonal bipyramid, edges with three equivalent S(6)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the fourth S site, S(4) is bonded in a 7-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), one S(7), and two equivalent S(1) atoms. In the fifth S site, S(5) is bonded to one Yb(1), one Yb(3), and three equivalent Yb(2) atoms to form distorted SYb5 trigonal bipyramids that share  a cornercorner with one S(7)Yb4S4 hexagonal bipyramid, corners with two equivalent S(3)Yb5 trigonal bipyramids, corners with two equivalent S(6)Yb5 trigonal bipyramids, edges with two equivalent S(3)Yb5 trigonal bipyramids, edges with two equivalent S(6)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the sixth S site, S(6) is bonded to one Yb(3), two equivalent Yb(1), and two equivalent Yb(2) atoms to form distorted SYb5 trigonal bipyramids that share corners with four equivalent S(5)Yb5 trigonal bipyramids,  an edgeedge with one S(7)Yb4S4 hexagonal bipyramid,  an edgeedge with one S(6)Yb5 trigonal bipyramid, edges with three equivalent S(3)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the seventh S site, S(7) is bonded to four equivalent Yb(1) and four equivalent S(4) atoms to form a mixture of distorted edge and corner-sharing SYb4S4 hexagonal bipyramids.
Yb16S29 crystallizes in the tetragonal I-42m space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 9-coordinate geometry to one S(1), one S(3), one S(7), two equivalent S(4), two equivalent S(5), and two equivalent S(6) atoms. The Yb(1)-S(1) bond length is 3.13 Å. The Yb(1)-S(3) bond length is 2.87 Å. The Yb(1)-S(7) bond length is 3.06 Å. Both Yb(1)-S(4) bond lengths are 2.97 Å. Both Yb(1)-S(5) bond lengths are 2.77 Å. Both Yb(1)-S(6) bond lengths are 2.75 Å. In the second Yb site, Yb(2) is bonded in a 8-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(6), and three equivalent S(5) atoms. The Yb(2)-S(1) bond length is 3.00 Å. The Yb(2)-S(2) bond length is 3.00 Å. The Yb(2)-S(3) bond length is 2.76 Å. The Yb(2)-S(4) bond length is 3.12 Å. The Yb(2)-S(6) bond length is 2.76 Å. There are two shorter (2.74 Å) and one longer (2.90 Å) Yb(2)-S(5) bond length. In the third Yb site, Yb(3) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(2), two equivalent S(3), and two equivalent S(5) atoms. The Yb(3)-S(1) bond length is 2.90 Å. The Yb(3)-S(6) bond length is 2.85 Å. Both Yb(3)-S(2) bond lengths are 3.03 Å. Both Yb(3)-S(3) bond lengths are 2.74 Å. Both Yb(3)-S(5) bond lengths are 2.78 Å. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(3), two equivalent Yb(2), two equivalent S(2), and two equivalent S(4) atoms. Both S(1)-S(2) bond lengths are 2.59 Å. Both S(1)-S(4) bond lengths are 2.80 Å. In the second S site, S(2) is bonded in a distorted hexagonal planar geometry to two equivalent Yb(2), two equivalent Yb(3), and two equivalent S(1) atoms. In the third S site, S(3) is bonded to one Yb(1), two equivalent Yb(2), and two equivalent Yb(3) atoms to form distorted SYb5 trigonal bipyramids that share  a cornercorner with one S(7)Yb4S4 hexagonal bipyramid, corners with four equivalent S(5)Yb5 trigonal bipyramids,  an edgeedge with one S(3)Yb5 trigonal bipyramid, edges with three equivalent S(6)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the fourth S site, S(4) is bonded in a 7-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), one S(7), and two equivalent S(1) atoms. The S(4)-S(7) bond length is 2.49 Å. In the fifth S site, S(5) is bonded to one Yb(1), one Yb(3), and three equivalent Yb(2) atoms to form distorted SYb5 trigonal bipyramids that share  a cornercorner with one S(7)Yb4S4 hexagonal bipyramid, corners with two equivalent S(3)Yb5 trigonal bipyramids, corners with two equivalent S(6)Yb5 trigonal bipyramids, edges with two equivalent S(3)Yb5 trigonal bipyramids, edges with two equivalent S(6)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the sixth S site, S(6) is bonded to one Yb(3), two equivalent Yb(1), and two equivalent Yb(2) atoms to form distorted SYb5 trigonal bipyramids that share corners with four equivalent S(5)Yb5 trigonal bipyramids,  an edgeedge with one S(7)Yb4S4 hexagonal bipyramid,  an edgeedge with one S(6)Yb5 trigonal bipyramid, edges with three equivalent S(3)Yb5 trigonal bipyramids, and edges with four equivalent S(5)Yb5 trigonal bipyramids. In the seventh S site, S(7) is bonded to four equivalent Yb(1) and four equivalent S(4) atoms to form a mixture of distorted edge and corner-sharing SYb4S4 hexagonal bipyramids.