Y5O4F7 crystallizes in the monoclinic C2 space group. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(1), one F(6), one F(7), and one F(8) atom. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(2), one F(6), one F(7), and one F(8) atom. In the third Y site, Y(3) is bonded in a 8-coordinate geometry to two equivalent O(5), one F(7), one F(8), two equivalent F(3), and two equivalent F(6) atoms. In the fourth Y site, Y(4) 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(2), one F(4), and one F(5) atom. In the fifth Y site, Y(5) 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(2), one F(4), and one F(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Y(2), one Y(4), and one Y(5) atom to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with two equivalent F(6)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(2)Y4 tetrahedra. In the second O site, O(2) is bonded to one Y(1), one Y(2), one Y(4), and one Y(5) atom to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra,  an edgeedge with one F(6)Y4 tetrahedra, and edges with two equivalent O(1)Y4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(4) and two equivalent Y(5) atoms to form a mixture of corner and edge-sharing OY4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(4) and two equivalent Y(5) atoms to form a mixture of corner and edge-sharing OY4 tetrahedra. In the fifth O site, O(5) is bonded to one Y(1), one Y(2), and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra, and edges with three equivalent F(6)Y4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(4), and one Y(5) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Y(2), one Y(4), and one Y(5) atom. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(3) atoms. In the fourth F site, F(4) is bonded in a 2-coordinate geometry to two equivalent Y(4) and two equivalent Y(5) atoms. In the fifth F site, F(5) is bonded in a 2-coordinate geometry to two equivalent Y(4) and two equivalent Y(5) atoms. In the sixth F site, F(6) is bonded to one Y(1), one Y(2), and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent F(6)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra, and edges with three equivalent O(5)Y4 tetrahedra. In the seventh F site, F(7) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom. In the eighth F site, F(8) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom.
Y5O4F7 crystallizes in the monoclinic C2 space group. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(1), one F(6), one F(7), and one F(8) atom. The Y(1)-O(1) bond length is 2.16 Å. The Y(1)-O(2) bond length is 2.28 Å. The Y(1)-O(5) bond length is 2.33 Å. The Y(1)-F(1) bond length is 2.25 Å. The Y(1)-F(6) bond length is 2.38 Å. The Y(1)-F(7) bond length is 2.27 Å. The Y(1)-F(8) bond length is 2.40 Å. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), one F(2), one F(6), one F(7), and one F(8) atom. The Y(2)-O(1) bond length is 2.22 Å. The Y(2)-O(2) bond length is 2.20 Å. The Y(2)-O(5) bond length is 2.31 Å. The Y(2)-F(2) bond length is 2.24 Å. The Y(2)-F(6) bond length is 2.35 Å. The Y(2)-F(7) bond length is 2.35 Å. The Y(2)-F(8) bond length is 2.35 Å. In the third Y site, Y(3) is bonded in a 8-coordinate geometry to two equivalent O(5), one F(7), one F(8), two equivalent F(3), and two equivalent F(6) atoms. There is one shorter (2.25 Å) and one longer (2.31 Å) Y(3)-O(5) bond length. The Y(3)-F(7) bond length is 2.39 Å. The Y(3)-F(8) bond length is 2.36 Å. There is one shorter (2.23 Å) and one longer (2.25 Å) Y(3)-F(3) bond length. There is one shorter (2.29 Å) and one longer (2.35 Å) Y(3)-F(6) bond length. In the fourth Y site, Y(4) 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(2), one F(4), and one F(5) atom. The Y(4)-O(1) bond length is 2.26 Å. The Y(4)-O(2) bond length is 2.35 Å. The Y(4)-O(3) bond length is 2.29 Å. The Y(4)-O(4) bond length is 2.20 Å. The Y(4)-F(1) bond length is 2.29 Å. The Y(4)-F(2) bond length is 2.53 Å. The Y(4)-F(4) bond length is 2.27 Å. The Y(4)-F(5) bond length is 2.80 Å. In the fifth Y site, Y(5) 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(2), one F(4), and one F(5) atom. The Y(5)-O(1) bond length is 2.31 Å. The Y(5)-O(2) bond length is 2.29 Å. The Y(5)-O(3) bond length is 2.22 Å. The Y(5)-O(4) bond length is 2.28 Å. The Y(5)-F(1) bond length is 2.49 Å. The Y(5)-F(2) bond length is 2.31 Å. The Y(5)-F(4) bond length is 2.81 Å. The Y(5)-F(5) bond length is 2.27 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Y(2), one Y(4), and one Y(5) atom to form OY4 tetrahedra that share corners with two equivalent O(4)Y4 tetrahedra, corners with two equivalent F(6)Y4 tetrahedra,  an edgeedge with one O(3)Y4 tetrahedra,  an edgeedge with one O(5)Y4 tetrahedra, and edges with two equivalent O(2)Y4 tetrahedra. In the second O site, O(2) is bonded to one Y(1), one Y(2), one Y(4), and one Y(5) atom to form OY4 tetrahedra that share corners with two equivalent O(3)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra,  an edgeedge with one O(4)Y4 tetrahedra,  an edgeedge with one F(6)Y4 tetrahedra, and edges with two equivalent O(1)Y4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Y(4) and two equivalent Y(5) atoms to form a mixture of corner and edge-sharing OY4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Y(4) and two equivalent Y(5) atoms to form a mixture of corner and edge-sharing OY4 tetrahedra. In the fifth O site, O(5) is bonded to one Y(1), one Y(2), and two equivalent Y(3) atoms to form OY4 tetrahedra that share corners with two equivalent O(2)Y4 tetrahedra, corners with two equivalent O(5)Y4 tetrahedra,  an edgeedge with one O(1)Y4 tetrahedra, and edges with three equivalent F(6)Y4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(4), and one Y(5) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Y(2), one Y(4), and one Y(5) atom. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Y(3) atoms. In the fourth F site, F(4) is bonded in a 2-coordinate geometry to two equivalent Y(4) and two equivalent Y(5) atoms. In the fifth F site, F(5) is bonded in a 2-coordinate geometry to two equivalent Y(4) and two equivalent Y(5) atoms. In the sixth F site, F(6) is bonded to one Y(1), one Y(2), and two equivalent Y(3) atoms to form FY4 tetrahedra that share corners with two equivalent O(1)Y4 tetrahedra, corners with two equivalent F(6)Y4 tetrahedra,  an edgeedge with one O(2)Y4 tetrahedra, and edges with three equivalent O(5)Y4 tetrahedra. In the seventh F site, F(7) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom. In the eighth F site, F(8) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom.