ThCrSe3 crystallizes in the orthorhombic Pnma space group. Th(1) is bonded in a 8-coordinate geometry to two equivalent Se(1) and six equivalent Se(2) atoms. Cr(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form corner-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Th(1) and two equivalent Cr(1) atoms to form distorted corner-sharing SeTh2Cr2 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to three equivalent Th(1) and two equivalent Cr(1) atoms.
ThCrSe3 crystallizes in the orthorhombic Pnma space group. Th(1) is bonded in a 8-coordinate geometry to two equivalent Se(1) and six equivalent Se(2) atoms. There is one shorter (2.92 Å) and one longer (2.98 Å) Th(1)-Se(1) bond length. There are a spread of Th(1)-Se(2) bond distances ranging from 3.00-3.25 Å. Cr(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form corner-sharing CrSe6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. Both Cr(1)-Se(1) bond lengths are 2.54 Å. There are two shorter (2.60 Å) and two longer (2.82 Å) Cr(1)-Se(2) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Th(1) and two equivalent Cr(1) atoms to form distorted corner-sharing SeTh2Cr2 trigonal pyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to three equivalent Th(1) and two equivalent Cr(1) atoms.