LiTbSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form LiSe6 octahedra that share corners with six equivalent Li(1)Se6 octahedra, edges with four equivalent Li(1)Se6 octahedra, and edges with eight equivalent Tb(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Tb(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form TbSe6 octahedra that share corners with six equivalent Tb(1)Se6 octahedra, edges with four equivalent Tb(1)Se6 octahedra, and edges with eight equivalent Li(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Li(1) and four equivalent Tb(1) atoms to form SeLi2Tb4 octahedra that share corners with six equivalent Se(1)Li2Tb4 octahedra, edges with four equivalent Se(1)Li2Tb4 octahedra, and edges with eight equivalent Se(2)Li4Tb2 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to four equivalent Li(1) and two equivalent Tb(1) atoms to form SeLi4Tb2 octahedra that share corners with six equivalent Se(2)Li4Tb2 octahedra, edges with four equivalent Se(2)Li4Tb2 octahedra, and edges with eight equivalent Se(1)Li2Tb4 octahedra. The corner-sharing octahedra are not tilted.
LiTbSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Li(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form LiSe6 octahedra that share corners with six equivalent Li(1)Se6 octahedra, edges with four equivalent Li(1)Se6 octahedra, and edges with eight equivalent Tb(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Both Li(1)-Se(1) bond lengths are 2.80 Å. All Li(1)-Se(2) bond lengths are 2.90 Å. Tb(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form TbSe6 octahedra that share corners with six equivalent Tb(1)Se6 octahedra, edges with four equivalent Tb(1)Se6 octahedra, and edges with eight equivalent Li(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Both Tb(1)-Se(2) bond lengths are 2.80 Å. All Tb(1)-Se(1) bond lengths are 2.90 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Li(1) and four equivalent Tb(1) atoms to form SeLi2Tb4 octahedra that share corners with six equivalent Se(1)Li2Tb4 octahedra, edges with four equivalent Se(1)Li2Tb4 octahedra, and edges with eight equivalent Se(2)Li4Tb2 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to four equivalent Li(1) and two equivalent Tb(1) atoms to form SeLi4Tb2 octahedra that share corners with six equivalent Se(2)Li4Tb2 octahedra, edges with four equivalent Se(2)Li4Tb2 octahedra, and edges with eight equivalent Se(1)Li2Tb4 octahedra. The corner-sharing octahedra are not tilted.