Y6O5F8 crystallizes in the monoclinic C2 space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one F(2), one F(5), one F(7), and one F(8) atom. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one F(1), one F(3), one F(5), and one F(6) atom. In the third Y site, Y(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(2), one F(3), one F(4), and one F(8) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(2) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra,  an edgeedge with one F(8)Y4 tetrahedra, and edges with two equivalent O(2)Y4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(2) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra, corners with two equivalent F(8)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(1)Y4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra, corners with two equivalent F(8)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(4)Y4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one F(8)Y4 tetrahedra, and edges with two equivalent O(3)Y4 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(4)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, edges with two equivalent F(2)Y4 tetrahedra, and edges with two equivalent F(8)Y4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Y(2) atoms. In the second F site, F(2) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(4)Y4 tetrahedra, corners with four equivalent F(8)Y4 tetrahedra, and edges with two equivalent O(5)Y4 tetrahedra. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(2) and two equivalent Y(3) atoms. In the fourth F site, F(4) is bonded in a linear geometry to two equivalent Y(3) atoms. In the fifth F site, F(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(1) and two equivalent Y(2) atoms. In the sixth F site, F(6) is bonded in a bent 150 degrees geometry to two equivalent Y(2) atoms. In the seventh F site, F(7) is bonded in a bent 150 degrees geometry to two equivalent Y(1) atoms. In the eighth F site, F(8) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra, and edges with two equivalent O(5)Y4 tetrahedra.
Y6O5F8 crystallizes in the monoclinic C2 space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), one F(2), one F(5), one F(7), and one F(8) atom. The Y(1)-O(3) bond length is 2.27 Å. The Y(1)-O(4) bond length is 2.27 Å. The Y(1)-O(5) bond length is 2.31 Å. The Y(1)-F(2) bond length is 2.60 Å. The Y(1)-F(5) bond length is 2.26 Å. The Y(1)-F(7) bond length is 2.20 Å. The Y(1)-F(8) bond length is 2.43 Å. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one F(1), one F(3), one F(5), and one F(6) atom. The Y(2)-O(1) bond length is 2.37 Å. The Y(2)-O(2) bond length is 2.25 Å. The Y(2)-O(3) bond length is 2.26 Å. The Y(2)-O(4) bond length is 2.36 Å. The Y(2)-F(1) bond length is 2.24 Å. The Y(2)-F(3) bond length is 2.77 Å. The Y(2)-F(5) bond length is 2.86 Å. The Y(2)-F(6) bond length is 2.27 Å. In the third Y site, Y(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(2), one F(3), one F(4), and one F(8) atom. The Y(3)-O(1) bond length is 2.28 Å. The Y(3)-O(2) bond length is 2.26 Å. The Y(3)-O(5) bond length is 2.32 Å. The Y(3)-F(2) bond length is 2.50 Å. The Y(3)-F(3) bond length is 2.30 Å. The Y(3)-F(4) bond length is 2.19 Å. The Y(3)-F(8) bond length is 2.44 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(2) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra,  an edgeedge with one F(8)Y4 tetrahedra, and edges with two equivalent O(2)Y4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Y(2) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra, corners with two equivalent F(8)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(1)Y4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra, corners with two equivalent F(8)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(4)Y4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(1) and two equivalent Y(2) atoms to form OY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra, corners with two equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one F(8)Y4 tetrahedra, and edges with two equivalent O(3)Y4 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(4)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra, edges with two equivalent F(2)Y4 tetrahedra, and edges with two equivalent F(8)Y4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Y(2) atoms. In the second F site, F(2) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(4)Y4 tetrahedra, corners with four equivalent F(8)Y4 tetrahedra, and edges with two equivalent O(5)Y4 tetrahedra. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(2) and two equivalent Y(3) atoms. In the fourth F site, F(4) is bonded in a linear geometry to two equivalent Y(3) atoms. In the fifth F site, F(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(1) and two equivalent Y(2) atoms. In the sixth F site, F(6) is bonded in a bent 150 degrees geometry to two equivalent Y(2) atoms. In the seventh F site, F(7) is bonded in a bent 150 degrees geometry to two equivalent Y(1) atoms. In the eighth F site, F(8) is bonded to two equivalent Y(1) and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(3)Y4 tetrahedra, corners with four equivalent F(2)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra, and edges with two equivalent O(5)Y4 tetrahedra.