Dy3NSe3 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 7-coordinate geometry to one N(1), two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms. In the second Dy site, Dy(2) is bonded in a 2-coordinate geometry to two equivalent N(1), one Se(1), one Se(3), and three equivalent Se(2) atoms. In the third Dy site, Dy(3) is bonded to one N(1), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted edge-sharing DySe5N octahedra. N(1) is bonded to one Dy(1), one Dy(3), and two equivalent Dy(2) atoms to form NDy4 tetrahedra that share corners with two equivalent Se(2)Dy5 square pyramids, corners with two equivalent N(1)Dy4 tetrahedra, and edges with three equivalent Se(2)Dy5 square pyramids. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one Dy(2), two equivalent Dy(1), and three equivalent Dy(3) atoms. In the second Se site, Se(2) is bonded to two equivalent Dy(1) and three equivalent Dy(2) atoms to form distorted SeDy5 square pyramids that share corners with two equivalent N(1)Dy4 tetrahedra, edges with four equivalent Se(2)Dy5 square pyramids, and edges with three equivalent N(1)Dy4 tetrahedra. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Dy(2), two equivalent Dy(1), and two equivalent Dy(3) atoms.
Dy3NSe3 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 7-coordinate geometry to one N(1), two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms. The Dy(1)-N(1) bond length is 2.23 Å. Both Dy(1)-Se(1) bond lengths are 3.24 Å. Both Dy(1)-Se(2) bond lengths are 2.81 Å. Both Dy(1)-Se(3) bond lengths are 2.99 Å. In the second Dy site, Dy(2) is bonded in a 2-coordinate geometry to two equivalent N(1), one Se(1), one Se(3), and three equivalent Se(2) atoms. Both Dy(2)-N(1) bond lengths are 2.31 Å. The Dy(2)-Se(1) bond length is 3.35 Å. The Dy(2)-Se(3) bond length is 2.96 Å. There is one shorter (2.87 Å) and two longer (3.04 Å) Dy(2)-Se(2) bond lengths. In the third Dy site, Dy(3) is bonded to one N(1), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted edge-sharing DySe5N octahedra. The Dy(3)-N(1) bond length is 2.17 Å. Both Dy(3)-Se(3) bond lengths are 2.91 Å. There are two shorter (2.82 Å) and one longer (3.13 Å) Dy(3)-Se(1) bond length. N(1) is bonded to one Dy(1), one Dy(3), and two equivalent Dy(2) atoms to form NDy4 tetrahedra that share corners with two equivalent Se(2)Dy5 square pyramids, corners with two equivalent N(1)Dy4 tetrahedra, and edges with three equivalent Se(2)Dy5 square pyramids. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one Dy(2), two equivalent Dy(1), and three equivalent Dy(3) atoms. In the second Se site, Se(2) is bonded to two equivalent Dy(1) and three equivalent Dy(2) atoms to form distorted SeDy5 square pyramids that share corners with two equivalent N(1)Dy4 tetrahedra, edges with four equivalent Se(2)Dy5 square pyramids, and edges with three equivalent N(1)Dy4 tetrahedra. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to one Dy(2), two equivalent Dy(1), and two equivalent Dy(3) atoms.