Zr3Se4 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing ZrSe6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the second Zr site, Zr(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form edge-sharing ZrSe6 octahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Zr(2) and four equivalent Zr(1) atoms to form a mixture of corner and edge-sharing SeZr5 square pyramids. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to two equivalent Zr(1) and two equivalent Zr(2) atoms.
Zr3Se4 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing ZrSe6 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. Both Zr(1)-Se(2) bond lengths are 2.68 Å. All Zr(1)-Se(1) bond lengths are 2.73 Å. In the second Zr site, Zr(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form edge-sharing ZrSe6 octahedra. Both Zr(2)-Se(1) bond lengths are 2.83 Å. All Zr(2)-Se(2) bond lengths are 2.77 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Zr(2) and four equivalent Zr(1) atoms to form a mixture of corner and edge-sharing SeZr5 square pyramids. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to two equivalent Zr(1) and two equivalent Zr(2) atoms.