CuGaSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal I4_1/amd space group. Cu(1) is bonded to six equivalent Se(1) atoms to form CuSe6 octahedra that share corners with two equivalent Ga(1)Se6 octahedra, corners with four equivalent Cu(1)Se6 octahedra, edges with four equivalent Cu(1)Se6 octahedra, and edges with eight equivalent Ga(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Ga(1) is bonded to six equivalent Se(1) atoms to form GaSe6 octahedra that share corners with two equivalent Cu(1)Se6 octahedra, corners with four equivalent Ga(1)Se6 octahedra, edges with four equivalent Ga(1)Se6 octahedra, and edges with eight equivalent Cu(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 three equivalent Cu(1) and three equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(1) is bonded to three equivalent Cu(1) and three equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedra are not tilted.
CuGaSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal I4_1/amd space group. Cu(1) is bonded to six equivalent Se(1) atoms to form CuSe6 octahedra that share corners with two equivalent Ga(1)Se6 octahedra, corners with four equivalent Cu(1)Se6 octahedra, edges with four equivalent Cu(1)Se6 octahedra, and edges with eight equivalent Ga(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are four shorter (2.65 Å) and two longer (2.67 Å) Cu(1)-Se(1) bond lengths. Ga(1) is bonded to six equivalent Se(1) atoms to form GaSe6 octahedra that share corners with two equivalent Cu(1)Se6 octahedra, corners with four equivalent Ga(1)Se6 octahedra, edges with four equivalent Ga(1)Se6 octahedra, and edges with eight equivalent Cu(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are four shorter (2.65 Å) and two longer (2.67 Å) Ga(1)-Se(1) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cu(1) and three equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(1) is bonded to three equivalent Cu(1) and three equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedra are not tilted. There are two shorter (2.65 Å) and one longer (2.67 Å) Se(1)-Cu(1) bond length. There are two shorter (2.65 Å) and one longer (2.67 Å) Se(1)-Ga(1) bond length.