Na4Zn3Se5 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one Se(1), two equivalent Se(2), and two equivalent Se(4) atoms. In the second Na site, Na(2) is bonded to two equivalent Se(1) and three equivalent Se(3) atoms to form NaSe5 square pyramids that share corners with three equivalent Na(3)Se6 octahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, edges with four equivalent Na(2)Se5 square pyramids,  an edgeedge with one Zn(2)Se4 tetrahedra, and edges with three equivalent Zn(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-54°. In the third Na site, Na(3) is bonded to one Se(3), two equivalent Se(4), and three equivalent Se(5) atoms to form distorted NaSe6 octahedra that share corners with three equivalent Na(2)Se5 square pyramids,  a cornercorner with one Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, edges with four equivalent Na(3)Se6 octahedra, edges with two equivalent Zn(1)Se4 tetrahedra, and edges with three equivalent Zn(3)Se4 tetrahedra. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one Se(3), two equivalent Se(2), and two equivalent Se(4) atoms. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one Se(1), one Se(5), and two equivalent Se(3) atoms to form ZnSe4 tetrahedra that share  a cornercorner with one Na(3)Se6 octahedra, corners with two equivalent Na(2)Se5 square pyramids, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with three equivalent Na(2)Se5 square pyramids. The corner-sharing octahedral tilt angles are 15°. In the second Zn site, Zn(2) is bonded to one Se(2), one Se(4), and two equivalent Se(1) atoms to form distorted ZnSe4 tetrahedra that share corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Na(2)Se5 square pyramids, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, and  an edgeedge with one Na(2)Se5 square pyramid. The corner-sharing octahedral tilt angles are 48°. In the third Zn site, Zn(3) is bonded to one Se(2), one Se(4), and two equivalent Se(5) atoms to form distorted ZnSe4 tetrahedra that share corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, and edges with three equivalent Na(3)Se6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are five inequivalent Se sites. In the first Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Na(1), two equivalent Na(4), one Zn(2), and one Zn(3) atom. In the second Se site, Se(3) is bonded in a 7-coordinate geometry to one Na(3), one Na(4), three equivalent Na(2), and two equivalent Zn(1) atoms. In the third Se site, Se(4) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(3), two equivalent Na(4), one Zn(2), and one Zn(3) atom. In the fourth Se site, Se(5) is bonded to three equivalent Na(3), one Zn(1), and two equivalent Zn(3) atoms to form a mixture of distorted corner and edge-sharing SeNa3Zn3 octahedra. The corner-sharing octahedral tilt angles are 73°. In the fifth Se site, Se(1) is bonded to one Na(1), two equivalent Na(2), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of distorted corner and edge-sharing SeNa3Zn3 octahedra. The corner-sharing octahedral tilt angles are 73°.
Na4Zn3Se5 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one Se(1), two equivalent Se(2), and two equivalent Se(4) atoms. The Na(1)-Se(1) bond length is 2.83 Å. Both Na(1)-Se(2) bond lengths are 2.89 Å. Both Na(1)-Se(4) bond lengths are 2.94 Å. In the second Na site, Na(2) is bonded to two equivalent Se(1) and three equivalent Se(3) atoms to form NaSe5 square pyramids that share corners with three equivalent Na(3)Se6 octahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, edges with four equivalent Na(2)Se5 square pyramids,  an edgeedge with one Zn(2)Se4 tetrahedra, and edges with three equivalent Zn(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-54°. Both Na(2)-Se(1) bond lengths are 3.08 Å. There is one shorter (3.08 Å) and two longer (3.13 Å) Na(2)-Se(3) bond lengths. In the third Na site, Na(3) is bonded to one Se(3), two equivalent Se(4), and three equivalent Se(5) atoms to form distorted NaSe6 octahedra that share corners with three equivalent Na(2)Se5 square pyramids,  a cornercorner with one Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, edges with four equivalent Na(3)Se6 octahedra, edges with two equivalent Zn(1)Se4 tetrahedra, and edges with three equivalent Zn(3)Se4 tetrahedra. The Na(3)-Se(3) bond length is 3.25 Å. Both Na(3)-Se(4) bond lengths are 2.99 Å. There are two shorter (3.02 Å) and one longer (3.07 Å) Na(3)-Se(5) bond length. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one Se(3), two equivalent Se(2), and two equivalent Se(4) atoms. The Na(4)-Se(3) bond length is 2.97 Å. Both Na(4)-Se(2) bond lengths are 2.89 Å. Both Na(4)-Se(4) bond lengths are 3.07 Å. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one Se(1), one Se(5), and two equivalent Se(3) atoms to form ZnSe4 tetrahedra that share  a cornercorner with one Na(3)Se6 octahedra, corners with two equivalent Na(2)Se5 square pyramids, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, edges with two equivalent Na(3)Se6 octahedra, and edges with three equivalent Na(2)Se5 square pyramids. The corner-sharing octahedral tilt angles are 15°. The Zn(1)-Se(1) bond length is 2.52 Å. The Zn(1)-Se(5) bond length is 2.52 Å. Both Zn(1)-Se(3) bond lengths are 2.53 Å. In the second Zn site, Zn(2) is bonded to one Se(2), one Se(4), and two equivalent Se(1) atoms to form distorted ZnSe4 tetrahedra that share corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Na(2)Se5 square pyramids, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, and  an edgeedge with one Na(2)Se5 square pyramid. The corner-sharing octahedral tilt angles are 48°. The Zn(2)-Se(2) bond length is 2.45 Å. The Zn(2)-Se(4) bond length is 2.61 Å. Both Zn(2)-Se(1) bond lengths are 2.55 Å. In the third Zn site, Zn(3) is bonded to one Se(2), one Se(4), and two equivalent Se(5) atoms to form distorted ZnSe4 tetrahedra that share corners with two equivalent Na(3)Se6 octahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, corners with two equivalent Zn(3)Se4 tetrahedra, and edges with three equivalent Na(3)Se6 octahedra. The corner-sharing octahedral tilt angles are 18°. The Zn(3)-Se(2) bond length is 2.48 Å. The Zn(3)-Se(4) bond length is 2.60 Å. Both Zn(3)-Se(5) bond lengths are 2.52 Å. There are five inequivalent Se sites. In the first Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Na(1), two equivalent Na(4), one Zn(2), and one Zn(3) atom. In the second Se site, Se(3) is bonded in a 7-coordinate geometry to one Na(3), one Na(4), three equivalent Na(2), and two equivalent Zn(1) atoms. In the third Se site, Se(4) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(3), two equivalent Na(4), one Zn(2), and one Zn(3) atom. In the fourth Se site, Se(5) is bonded to three equivalent Na(3), one Zn(1), and two equivalent Zn(3) atoms to form a mixture of distorted corner and edge-sharing SeNa3Zn3 octahedra. The corner-sharing octahedral tilt angles are 73°. In the fifth Se site, Se(1) is bonded to one Na(1), two equivalent Na(2), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of distorted corner and edge-sharing SeNa3Zn3 octahedra. The corner-sharing octahedral tilt angles are 73°.