Cs2ZrSe3 crystallizes in the orthorhombic Cmcm space group. Cs(1) is bonded in a 7-coordinate geometry to three equivalent Se(1) and four equivalent Se(2) atoms. Zr(1) is bonded to one Se(1) and four equivalent Se(2) atoms to form distorted edge-sharing ZrSe5 trigonal bipyramids. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted single-bond geometry to six equivalent Cs(1) and one Zr(1) atom. In the second Se site, Se(2) is bonded to four equivalent Cs(1) and two equivalent Zr(1) atoms to form a mixture of distorted edge, corner, and face-sharing SeCs4Zr2 octahedra. The corner-sharing octahedral tilt angles range from 34-48°.
Cs2ZrSe3 crystallizes in the orthorhombic Cmcm space group. Cs(1) is bonded in a 7-coordinate geometry to three equivalent Se(1) and four equivalent Se(2) atoms. There is one shorter (3.70 Å) and two longer (4.14 Å) Cs(1)-Se(1) bond lengths. There are two shorter (3.65 Å) and two longer (3.71 Å) Cs(1)-Se(2) bond lengths. Zr(1) is bonded to one Se(1) and four equivalent Se(2) atoms to form distorted edge-sharing ZrSe5 trigonal bipyramids. The Zr(1)-Se(1) bond length is 2.49 Å. All Zr(1)-Se(2) bond lengths are 2.66 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted single-bond geometry to six equivalent Cs(1) and one Zr(1) atom. In the second Se site, Se(2) is bonded to four equivalent Cs(1) and two equivalent Zr(1) atoms to form a mixture of distorted edge, corner, and face-sharing SeCs4Zr2 octahedra. The corner-sharing octahedral tilt angles range from 34-48°.