TlNdSe2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. Nd(1) is bonded to six equivalent Se(1) atoms to form NdSe6 octahedra that share corners with six equivalent Tl(1)Se6 octahedra, edges with six equivalent Nd(1)Se6 octahedra, and edges with six equivalent Tl(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 9°. Tl(1) is bonded to six equivalent Se(1) atoms to form distorted TlSe6 octahedra that share corners with six equivalent Nd(1)Se6 octahedra, edges with six equivalent Nd(1)Se6 octahedra, and edges with six equivalent Tl(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 9°. Se(1) is bonded to three equivalent Nd(1) and three equivalent Tl(1) atoms to form a mixture of distorted corner and edge-sharing SeNd3Tl3 octahedra. The corner-sharing octahedra are not tilted.
TlNdSe2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. Nd(1) is bonded to six equivalent Se(1) atoms to form NdSe6 octahedra that share corners with six equivalent Tl(1)Se6 octahedra, edges with six equivalent Nd(1)Se6 octahedra, and edges with six equivalent Tl(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 9°. All Nd(1)-Se(1) bond lengths are 2.98 Å. Tl(1) is bonded to six equivalent Se(1) atoms to form distorted TlSe6 octahedra that share corners with six equivalent Nd(1)Se6 octahedra, edges with six equivalent Nd(1)Se6 octahedra, and edges with six equivalent Tl(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 9°. All Tl(1)-Se(1) bond lengths are 3.34 Å. Se(1) is bonded to three equivalent Nd(1) and three equivalent Tl(1) atoms to form a mixture of distorted corner and edge-sharing SeNd3Tl3 octahedra. The corner-sharing octahedra are not tilted.