Tm2CdSe4 is Spinel structured and crystallizes in the cubic Fd-3m space group. Tm(1) is bonded to six equivalent Se(1) atoms to form TmSe6 octahedra that share corners with six equivalent Cd(1)Se4 tetrahedra and edges with six equivalent Tm(1)Se6 octahedra. Cd(1) is bonded to four equivalent Se(1) atoms to form CdSe4 tetrahedra that share corners with twelve equivalent Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 57°. Se(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Tm(1) and one Cd(1) atom.
Tm2CdSe4 is Spinel structured and crystallizes in the cubic Fd-3m space group. Tm(1) is bonded to six equivalent Se(1) atoms to form TmSe6 octahedra that share corners with six equivalent Cd(1)Se4 tetrahedra and edges with six equivalent Tm(1)Se6 octahedra. All Tm(1)-Se(1) bond lengths are 2.82 Å. Cd(1) is bonded to four equivalent Se(1) atoms to form CdSe4 tetrahedra that share corners with twelve equivalent Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cd(1)-Se(1) bond lengths are 2.67 Å. Se(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Tm(1) and one Cd(1) atom.