Ce2SeS is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Se(1) and two equivalent S(1) atoms to form CeSe4S2 octahedra that share corners with six equivalent Ce(1)Se4S2 octahedra, edges with four equivalent Ce(1)Se4S2 octahedra, and edges with eight equivalent Ce(2)Se2S4 octahedra. The corner-sharing octahedra are not tilted. In the second Ce site, Ce(2) is bonded to two equivalent Se(1) and four equivalent S(1) atoms to form CeSe2S4 octahedra that share corners with six equivalent Ce(2)Se2S4 octahedra, edges with four equivalent Ce(2)Se2S4 octahedra, and edges with eight equivalent Ce(1)Se4S2 octahedra. The corner-sharing octahedra are not tilted. Se(1) is bonded to two equivalent Ce(2) and four equivalent Ce(1) atoms to form SeCe6 octahedra that share corners with six equivalent Se(1)Ce6 octahedra, edges with four equivalent Se(1)Ce6 octahedra, and edges with eight equivalent S(1)Ce6 octahedra. The corner-sharing octahedra are not tilted. S(1) is bonded to two equivalent Ce(1) and four equivalent Ce(2) atoms to form SCe6 octahedra that share corners with six equivalent S(1)Ce6 octahedra, edges with four equivalent S(1)Ce6 octahedra, and edges with eight equivalent Se(1)Ce6 octahedra. The corner-sharing octahedra are not tilted.
Ce2SeS is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Se(1) and two equivalent S(1) atoms to form CeSe4S2 octahedra that share corners with six equivalent Ce(1)Se4S2 octahedra, edges with four equivalent Ce(1)Se4S2 octahedra, and edges with eight equivalent Ce(2)Se2S4 octahedra. The corner-sharing octahedra are not tilted. All Ce(1)-Se(1) bond lengths are 2.91 Å. Both Ce(1)-S(1) bond lengths are 2.91 Å. In the second Ce site, Ce(2) is bonded to two equivalent Se(1) and four equivalent S(1) atoms to form CeSe2S4 octahedra that share corners with six equivalent Ce(2)Se2S4 octahedra, edges with four equivalent Ce(2)Se2S4 octahedra, and edges with eight equivalent Ce(1)Se4S2 octahedra. The corner-sharing octahedra are not tilted. Both Ce(2)-Se(1) bond lengths are 2.91 Å. All Ce(2)-S(1) bond lengths are 2.91 Å. Se(1) is bonded to two equivalent Ce(2) and four equivalent Ce(1) atoms to form SeCe6 octahedra that share corners with six equivalent Se(1)Ce6 octahedra, edges with four equivalent Se(1)Ce6 octahedra, and edges with eight equivalent S(1)Ce6 octahedra. The corner-sharing octahedra are not tilted. S(1) is bonded to two equivalent Ce(1) and four equivalent Ce(2) atoms to form SCe6 octahedra that share corners with six equivalent S(1)Ce6 octahedra, edges with four equivalent S(1)Ce6 octahedra, and edges with eight equivalent Se(1)Ce6 octahedra. The corner-sharing octahedra are not tilted.