Yb3Y(Si2O7)2 crystallizes in the triclinic P1 space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(12), one O(14), one O(4), one O(6), one O(8), and one O(9) atom to form distorted YbO6 octahedra that share  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Yb(2)O6 octahedra, and edges with two equivalent Yb(3)O6 pentagonal pyramids. In the second Yb site, Yb(2) is bonded to one O(11), one O(13), one O(3), one O(6), one O(7), and one O(9) atom to form distorted YbO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra,  an edgeedge with one Yb(1)O6 octahedra, and edges with two equivalent Y(1)O6 octahedra. In the third Yb site, Yb(3) is bonded to one O(10), one O(12), one O(14), one O(4), one O(5), and one O(8) atom to form distorted YbO6 pentagonal pyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(4)O4 tetrahedra,  an edgeedge with one Y(1)O6 octahedra, and edges with two equivalent Yb(1)O6 octahedra. Y(1) is bonded to one O(10), one O(11), one O(13), one O(3), one O(5), and one O(7) atom to form distorted YO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, edges with two equivalent Yb(2)O6 octahedra, and  an edgeedge with one Yb(3)O6 pentagonal pyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(11), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Yb(2)O6 octahedra, corners with three equivalent Y(1)O6 octahedra,  a cornercorner with one Yb(3)O6 pentagonal pyramid, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-59°. In the second Si site, Si(2) is bonded to one O(12), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Yb(2)O6 octahedra, corners with three equivalent Yb(1)O6 octahedra, corners with two equivalent Yb(3)O6 pentagonal pyramids, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-56°. In the third Si site, Si(3) is bonded to one O(13), one O(2), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Yb(1)O6 octahedra, corners with two equivalent Y(1)O6 octahedra, corners with three equivalent Yb(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the fourth Si site, Si(4) is bonded to one O(1), one O(10), one O(14), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra, corners with two equivalent Yb(1)O6 octahedra, corners with three equivalent Yb(3)O6 pentagonal pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-56°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Si(1) and one Si(4) atom. In the second O site, O(2) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Yb(3), one Y(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(2), and one Si(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Yb(3), one Y(1), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(4) atom.
Yb3Y(Si2O7)2 crystallizes in the triclinic P1 space group. There are three inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(12), one O(14), one O(4), one O(6), one O(8), and one O(9) atom to form distorted YbO6 octahedra that share  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra,  an edgeedge with one Yb(2)O6 octahedra, and edges with two equivalent Yb(3)O6 pentagonal pyramids. The Yb(1)-O(12) bond length is 2.33 Å. The Yb(1)-O(14) bond length is 2.36 Å. The Yb(1)-O(4) bond length is 2.30 Å. The Yb(1)-O(6) bond length is 2.35 Å. The Yb(1)-O(8) bond length is 2.33 Å. The Yb(1)-O(9) bond length is 2.30 Å. In the second Yb site, Yb(2) is bonded to one O(11), one O(13), one O(3), one O(6), one O(7), and one O(9) atom to form distorted YbO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra,  an edgeedge with one Yb(1)O6 octahedra, and edges with two equivalent Y(1)O6 octahedra. The Yb(2)-O(11) bond length is 2.35 Å. The Yb(2)-O(13) bond length is 2.35 Å. The Yb(2)-O(3) bond length is 2.37 Å. The Yb(2)-O(6) bond length is 2.30 Å. The Yb(2)-O(7) bond length is 2.31 Å. The Yb(2)-O(9) bond length is 2.34 Å. In the third Yb site, Yb(3) is bonded to one O(10), one O(12), one O(14), one O(4), one O(5), and one O(8) atom to form distorted YbO6 pentagonal pyramids that share  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Si(4)O4 tetrahedra,  an edgeedge with one Y(1)O6 octahedra, and edges with two equivalent Yb(1)O6 octahedra. The Yb(3)-O(10) bond length is 2.37 Å. The Yb(3)-O(12) bond length is 2.33 Å. The Yb(3)-O(14) bond length is 2.34 Å. The Yb(3)-O(4) bond length is 2.34 Å. The Yb(3)-O(5) bond length is 2.31 Å. The Yb(3)-O(8) bond length is 2.29 Å. Y(1) is bonded to one O(10), one O(11), one O(13), one O(3), one O(5), and one O(7) atom to form distorted YO6 octahedra that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, edges with two equivalent Yb(2)O6 octahedra, and  an edgeedge with one Yb(3)O6 pentagonal pyramid. The Y(1)-O(10) bond length is 2.25 Å. The Y(1)-O(11) bond length is 2.32 Å. The Y(1)-O(13) bond length is 2.31 Å. The Y(1)-O(3) bond length is 2.25 Å. The Y(1)-O(5) bond length is 2.29 Å. The Y(1)-O(7) bond length is 2.30 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(11), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Yb(2)O6 octahedra, corners with three equivalent Y(1)O6 octahedra,  a cornercorner with one Yb(3)O6 pentagonal pyramid, and  a cornercorner with one Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-59°. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(11) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(12), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Yb(2)O6 octahedra, corners with three equivalent Yb(1)O6 octahedra, corners with two equivalent Yb(3)O6 pentagonal pyramids, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-56°. The Si(2)-O(12) bond length is 1.64 Å. The Si(2)-O(2) bond length is 1.65 Å. The Si(2)-O(4) bond length is 1.63 Å. The Si(2)-O(6) bond length is 1.63 Å. In the third Si site, Si(3) is bonded to one O(13), one O(2), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Yb(1)O6 octahedra, corners with two equivalent Y(1)O6 octahedra, corners with three equivalent Yb(2)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Si(3)-O(13) bond length is 1.64 Å. The Si(3)-O(2) bond length is 1.66 Å. The Si(3)-O(7) bond length is 1.63 Å. The Si(3)-O(9) bond length is 1.63 Å. In the fourth Si site, Si(4) is bonded to one O(1), one O(10), one O(14), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra, corners with two equivalent Yb(1)O6 octahedra, corners with three equivalent Yb(3)O6 pentagonal pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-56°. The Si(4)-O(1) bond length is 1.66 Å. The Si(4)-O(10) bond length is 1.63 Å. The Si(4)-O(14) bond length is 1.64 Å. The Si(4)-O(8) bond length is 1.62 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Si(1) and one Si(4) atom. In the second O site, O(2) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Yb(3), one Y(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(2), and one Si(3) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Yb(3), one Y(1), and one Si(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(2) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Yb(2), one Y(1), and one Si(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Yb(1), one Yb(3), and one Si(4) atom.