YbTb10Se16 crystallizes in the tetragonal P-4 space group. Yb(1) is bonded in a 8-coordinate geometry to four equivalent Se(3) and four equivalent Se(4) atoms. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 8-coordinate geometry to one Se(2), one Se(4), three equivalent Se(1), and three equivalent Se(3) atoms. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. In the third Tb site, Tb(3) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), three equivalent Se(2), and three equivalent Se(4) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted SeTb5 trigonal bipyramids that share corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids,  a cornercorner with one Se(1)Tb5 trigonal bipyramid,  an edgeedge with one Se(3)Tb5Yb octahedra, edges with two equivalent Se(4)Tb5Yb octahedra, edges with two equivalent Se(2)Tb5 square pyramids, edges with three equivalent Se(1)Tb5 trigonal bipyramids, and faces with two equivalent Se(3)Tb5Yb octahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the second Se site, Se(2) is bonded to one Tb(1), one Tb(2), and three equivalent Tb(3) atoms to form distorted SeTb5 square pyramids that share corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(4)Tb5Yb octahedra, edges with two equivalent Se(3)Tb5Yb octahedra, edges with two equivalent Se(1)Tb5 trigonal bipyramids, faces with two equivalent Se(4)Tb5Yb octahedra, and  a faceface with one Se(2)Tb5 square pyramid. The corner-sharing octahedral tilt angles range from 16-53°. In the third Se site, Se(3) is bonded to one Yb(1), one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted SeTb5Yb octahedra that share corners with three equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(4)Tb5Yb octahedra, edges with two equivalent Se(3)Tb5Yb octahedra, edges with two equivalent Se(2)Tb5 square pyramids,  an edgeedge with one Se(1)Tb5 trigonal bipyramid,  a faceface with one Se(3)Tb5Yb octahedra, faces with two equivalent Se(4)Tb5Yb octahedra, and faces with two equivalent Se(1)Tb5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 20-48°. In the fourth Se site, Se(4) is bonded to one Yb(1), one Tb(1), one Tb(2), and three equivalent Tb(3) atoms to form distorted SeTb5Yb octahedra that share corners with three equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(3)Tb5Yb octahedra, edges with two equivalent Se(4)Tb5Yb octahedra,  an edgeedge with one Se(2)Tb5 square pyramid, edges with two equivalent Se(1)Tb5 trigonal bipyramids,  a faceface with one Se(4)Tb5Yb octahedra, faces with two equivalent Se(3)Tb5Yb octahedra, and faces with two equivalent Se(2)Tb5 square pyramids. The corner-sharing octahedral tilt angles range from 21-48°.
YbTb10Se16 crystallizes in the tetragonal P-4 space group. Yb(1) is bonded in a 8-coordinate geometry to four equivalent Se(3) and four equivalent Se(4) atoms. All Yb(1)-Se(3) bond lengths are 2.90 Å. All Yb(1)-Se(4) bond lengths are 3.16 Å. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 8-coordinate geometry to one Se(2), one Se(4), three equivalent Se(1), and three equivalent Se(3) atoms. The Tb(1)-Se(2) bond length is 2.86 Å. The Tb(1)-Se(4) bond length is 3.13 Å. There are a spread of Tb(1)-Se(1) bond distances ranging from 2.86-3.15 Å. There are a spread of Tb(1)-Se(3) bond distances ranging from 2.90-3.22 Å. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. Both Tb(2)-Se(1) bond lengths are 2.87 Å. Both Tb(2)-Se(2) bond lengths are 3.11 Å. Both Tb(2)-Se(3) bond lengths are 3.15 Å. Both Tb(2)-Se(4) bond lengths are 2.88 Å. In the third Tb site, Tb(3) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), three equivalent Se(2), and three equivalent Se(4) atoms. The Tb(3)-Se(1) bond length is 3.13 Å. The Tb(3)-Se(3) bond length is 2.90 Å. There are a spread of Tb(3)-Se(2) bond distances ranging from 2.85-3.13 Å. There are a spread of Tb(3)-Se(4) bond distances ranging from 2.87-3.29 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted SeTb5 trigonal bipyramids that share corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids,  a cornercorner with one Se(1)Tb5 trigonal bipyramid,  an edgeedge with one Se(3)Tb5Yb octahedra, edges with two equivalent Se(4)Tb5Yb octahedra, edges with two equivalent Se(2)Tb5 square pyramids, edges with three equivalent Se(1)Tb5 trigonal bipyramids, and faces with two equivalent Se(3)Tb5Yb octahedra. The corner-sharing octahedral tilt angles range from 21-50°. In the second Se site, Se(2) is bonded to one Tb(1), one Tb(2), and three equivalent Tb(3) atoms to form distorted SeTb5 square pyramids that share corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(4)Tb5Yb octahedra, edges with two equivalent Se(3)Tb5Yb octahedra, edges with two equivalent Se(1)Tb5 trigonal bipyramids, faces with two equivalent Se(4)Tb5Yb octahedra, and  a faceface with one Se(2)Tb5 square pyramid. The corner-sharing octahedral tilt angles range from 16-53°. In the third Se site, Se(3) is bonded to one Yb(1), one Tb(2), one Tb(3), and three equivalent Tb(1) atoms to form distorted SeTb5Yb octahedra that share corners with three equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(4)Tb5Yb octahedra, edges with two equivalent Se(3)Tb5Yb octahedra, edges with two equivalent Se(2)Tb5 square pyramids,  an edgeedge with one Se(1)Tb5 trigonal bipyramid,  a faceface with one Se(3)Tb5Yb octahedra, faces with two equivalent Se(4)Tb5Yb octahedra, and faces with two equivalent Se(1)Tb5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 20-48°. In the fourth Se site, Se(4) is bonded to one Yb(1), one Tb(1), one Tb(2), and three equivalent Tb(3) atoms to form distorted SeTb5Yb octahedra that share corners with three equivalent Se(4)Tb5Yb octahedra, corners with four equivalent Se(3)Tb5Yb octahedra, corners with four equivalent Se(2)Tb5 square pyramids, corners with four equivalent Se(1)Tb5 trigonal bipyramids,  an edgeedge with one Se(3)Tb5Yb octahedra, edges with two equivalent Se(4)Tb5Yb octahedra,  an edgeedge with one Se(2)Tb5 square pyramid, edges with two equivalent Se(1)Tb5 trigonal bipyramids,  a faceface with one Se(4)Tb5Yb octahedra, faces with two equivalent Se(3)Tb5Yb octahedra, and faces with two equivalent Se(2)Tb5 square pyramids. The corner-sharing octahedral tilt angles range from 21-48°.