Yb5(ReO6)2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(4) atoms. In the second Yb site, Yb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(4), and four equivalent O(2) atoms. In the third Yb site, Yb(3) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form YbO6 octahedra that share corners with four equivalent Re(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. Re(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form ReO6 octahedra that share corners with two equivalent Yb(3)O6 octahedra and edges with two equivalent Re(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Yb(3) and two equivalent Re(1) atoms. In the second O site, O(2) is bonded to one Yb(1), two equivalent Yb(2), and one Re(1) atom to form distorted OYb3Re tetrahedra that share  a cornercorner with one O(3)Yb2Re2 tetrahedra, corners with four equivalent O(2)Yb3Re tetrahedra, corners with six equivalent O(4)Yb4 tetrahedra,  an edgeedge with one O(4)Yb4 tetrahedra, edges with two equivalent O(3)Yb2Re2 tetrahedra, and edges with two equivalent O(2)Yb3Re tetrahedra. In the third O site, O(3) is bonded to one Yb(1), one Yb(2), and two equivalent Re(1) atoms to form distorted OYb2Re2 tetrahedra that share corners with two equivalent O(2)Yb3Re tetrahedra, corners with six equivalent O(4)Yb4 tetrahedra,  an edgeedge with one O(3)Yb2Re2 tetrahedra, and edges with four equivalent O(2)Yb3Re tetrahedra. In the fourth O site, O(4) is bonded to one Yb(2), one Yb(3), and two equivalent Yb(1) atoms to form OYb4 tetrahedra that share corners with three equivalent O(3)Yb2Re2 tetrahedra, corners with four equivalent O(4)Yb4 tetrahedra, corners with six equivalent O(2)Yb3Re tetrahedra,  an edgeedge with one O(2)Yb3Re tetrahedra, and edges with three equivalent O(4)Yb4 tetrahedra.
Yb5(ReO6)2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(4) atoms. The Yb(1)-O(3) bond length is 2.41 Å. Both Yb(1)-O(2) bond lengths are 2.54 Å. There are two shorter (2.30 Å) and two longer (2.32 Å) Yb(1)-O(4) bond lengths. In the second Yb site, Yb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(4), and four equivalent O(2) atoms. The Yb(2)-O(3) bond length is 2.34 Å. Both Yb(2)-O(4) bond lengths are 2.27 Å. There are two shorter (2.37 Å) and two longer (2.54 Å) Yb(2)-O(2) bond lengths. In the third Yb site, Yb(3) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form YbO6 octahedra that share corners with four equivalent Re(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. Both Yb(3)-O(1) bond lengths are 2.35 Å. All Yb(3)-O(4) bond lengths are 2.32 Å. Re(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form ReO6 octahedra that share corners with two equivalent Yb(3)O6 octahedra and edges with two equivalent Re(1)O6 octahedra. The corner-sharing octahedral tilt angles are 41°. Both Re(1)-O(1) bond lengths are 1.98 Å. Both Re(1)-O(2) bond lengths are 1.84 Å. Both Re(1)-O(3) bond lengths are 2.03 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Yb(3) and two equivalent Re(1) atoms. In the second O site, O(2) is bonded to one Yb(1), two equivalent Yb(2), and one Re(1) atom to form distorted OYb3Re tetrahedra that share  a cornercorner with one O(3)Yb2Re2 tetrahedra, corners with four equivalent O(2)Yb3Re tetrahedra, corners with six equivalent O(4)Yb4 tetrahedra,  an edgeedge with one O(4)Yb4 tetrahedra, edges with two equivalent O(3)Yb2Re2 tetrahedra, and edges with two equivalent O(2)Yb3Re tetrahedra. In the third O site, O(3) is bonded to one Yb(1), one Yb(2), and two equivalent Re(1) atoms to form distorted OYb2Re2 tetrahedra that share corners with two equivalent O(2)Yb3Re tetrahedra, corners with six equivalent O(4)Yb4 tetrahedra,  an edgeedge with one O(3)Yb2Re2 tetrahedra, and edges with four equivalent O(2)Yb3Re tetrahedra. In the fourth O site, O(4) is bonded to one Yb(2), one Yb(3), and two equivalent Yb(1) atoms to form OYb4 tetrahedra that share corners with three equivalent O(3)Yb2Re2 tetrahedra, corners with four equivalent O(4)Yb4 tetrahedra, corners with six equivalent O(2)Yb3Re tetrahedra,  an edgeedge with one O(2)Yb3Re tetrahedra, and edges with three equivalent O(4)Yb4 tetrahedra.