BaY2(Si2O7)F2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), two equivalent O(4), one F(1), and one F(2) atom. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(7), and two equivalent O(2) atoms. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(6), two equivalent F(1), and two equivalent F(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Y(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Y(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Y(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Ba(1), one Y(1), one Y(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Y(2), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(2), and one Si(1) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal non-coplanar geometry to one Ba(1) and two equivalent Y(2) atoms. In the second F site, F(2) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Y(2) atoms.
BaY2(Si2O7)F2 crystallizes in the triclinic P-1 space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), two equivalent O(4), one F(1), and one F(2) atom. The Ba(1)-O(1) bond length is 2.98 Å. The Ba(1)-O(2) bond length is 3.07 Å. The Ba(1)-O(3) bond length is 2.84 Å. The Ba(1)-O(5) bond length is 2.72 Å. The Ba(1)-O(6) bond length is 2.87 Å. There is one shorter (2.79 Å) and one longer (3.03 Å) Ba(1)-O(4) bond length. The Ba(1)-F(1) bond length is 2.64 Å. The Ba(1)-F(2) bond length is 2.74 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(7), and two equivalent O(2) atoms. The Y(1)-O(1) bond length is 2.69 Å. The Y(1)-O(3) bond length is 2.25 Å. The Y(1)-O(4) bond length is 2.27 Å. The Y(1)-O(5) bond length is 2.37 Å. The Y(1)-O(7) bond length is 2.36 Å. There is one shorter (2.28 Å) and one longer (2.41 Å) Y(1)-O(2) bond length. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(6), two equivalent F(1), and two equivalent F(2) atoms. The Y(2)-O(5) bond length is 2.45 Å. The Y(2)-O(7) bond length is 2.37 Å. There is one shorter (2.32 Å) and one longer (2.46 Å) Y(2)-O(6) bond length. There is one shorter (2.22 Å) and one longer (2.48 Å) Y(2)-F(1) bond length. There is one shorter (2.28 Å) and one longer (2.39 Å) Y(2)-F(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.69 Å. The Si(1)-O(5) bond length is 1.65 Å. The Si(1)-O(6) bond length is 1.63 Å. The Si(1)-O(7) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. The Si(2)-O(1) bond length is 1.71 Å. The Si(2)-O(2) bond length is 1.66 Å. The Si(2)-O(3) bond length is 1.62 Å. The Si(2)-O(4) bond length is 1.64 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Y(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Y(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Y(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Ba(1), one Y(1), one Y(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Y(2), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(2), and one Si(1) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal non-coplanar geometry to one Ba(1) and two equivalent Y(2) atoms. In the second F site, F(2) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Y(2) atoms.