Dy2SeOF2 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 4-coordinate geometry to four equivalent Se(1), three equivalent O(1), and one F(2) atom. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to two equivalent Se(1), one O(1), three equivalent F(1), and three equivalent F(2) atoms. Se(1) is bonded to two equivalent Dy(2) and four equivalent Dy(1) atoms to form distorted SeDy6 pentagonal pyramids that share corners with four equivalent Se(1)Dy6 pentagonal pyramids, corners with four equivalent F(2)Dy4 tetrahedra, corners with six equivalent O(1)Dy4 tetrahedra, edges with two equivalent Se(1)Dy6 pentagonal pyramids, edges with three equivalent F(2)Dy4 tetrahedra, edges with four equivalent O(1)Dy4 tetrahedra, and faces with two equivalent Se(1)Dy6 pentagonal pyramids. O(1) is bonded to one Dy(2) and three equivalent Dy(1) atoms to form ODy4 tetrahedra that share corners with six equivalent Se(1)Dy6 pentagonal pyramids, corners with two equivalent O(1)Dy4 tetrahedra, corners with two equivalent F(2)Dy4 tetrahedra, edges with four equivalent Se(1)Dy6 pentagonal pyramids, edges with two equivalent O(1)Dy4 tetrahedra, and edges with two equivalent F(2)Dy4 tetrahedra. There are two inequivalent F sites. In the first F site, F(1) is bonded in a trigonal non-coplanar geometry to three equivalent Dy(2) atoms. In the second F site, F(2) is bonded to one Dy(1) and three equivalent Dy(2) atoms to form FDy4 tetrahedra that share corners with four equivalent Se(1)Dy6 pentagonal pyramids, corners with two equivalent O(1)Dy4 tetrahedra, corners with six equivalent F(2)Dy4 tetrahedra, edges with three equivalent Se(1)Dy6 pentagonal pyramids, and edges with two equivalent O(1)Dy4 tetrahedra.
Dy2SeOF2 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 4-coordinate geometry to four equivalent Se(1), three equivalent O(1), and one F(2) atom. There are two shorter (3.03 Å) and two longer (3.05 Å) Dy(1)-Se(1) bond lengths. There is one shorter (2.26 Å) and two longer (2.27 Å) Dy(1)-O(1) bond lengths. The Dy(1)-F(2) bond length is 2.42 Å. In the second Dy site, Dy(2) is bonded in a 7-coordinate geometry to two equivalent Se(1), one O(1), three equivalent F(1), and three equivalent F(2) atoms. Both Dy(2)-Se(1) bond lengths are 3.05 Å. The Dy(2)-O(1) bond length is 2.27 Å. There is one shorter (2.36 Å) and two longer (2.40 Å) Dy(2)-F(1) bond lengths. There are two shorter (2.36 Å) and one longer (2.43 Å) Dy(2)-F(2) bond length. Se(1) is bonded to two equivalent Dy(2) and four equivalent Dy(1) atoms to form distorted SeDy6 pentagonal pyramids that share corners with four equivalent Se(1)Dy6 pentagonal pyramids, corners with four equivalent F(2)Dy4 tetrahedra, corners with six equivalent O(1)Dy4 tetrahedra, edges with two equivalent Se(1)Dy6 pentagonal pyramids, edges with three equivalent F(2)Dy4 tetrahedra, edges with four equivalent O(1)Dy4 tetrahedra, and faces with two equivalent Se(1)Dy6 pentagonal pyramids. O(1) is bonded to one Dy(2) and three equivalent Dy(1) atoms to form ODy4 tetrahedra that share corners with six equivalent Se(1)Dy6 pentagonal pyramids, corners with two equivalent O(1)Dy4 tetrahedra, corners with two equivalent F(2)Dy4 tetrahedra, edges with four equivalent Se(1)Dy6 pentagonal pyramids, edges with two equivalent O(1)Dy4 tetrahedra, and edges with two equivalent F(2)Dy4 tetrahedra. There are two inequivalent F sites. In the first F site, F(1) is bonded in a trigonal non-coplanar geometry to three equivalent Dy(2) atoms. In the second F site, F(2) is bonded to one Dy(1) and three equivalent Dy(2) atoms to form FDy4 tetrahedra that share corners with four equivalent Se(1)Dy6 pentagonal pyramids, corners with two equivalent O(1)Dy4 tetrahedra, corners with six equivalent F(2)Dy4 tetrahedra, edges with three equivalent Se(1)Dy6 pentagonal pyramids, and edges with two equivalent O(1)Dy4 tetrahedra.