Materials Data on GaCuSe2 by Materials Project
CuGaSe2 is Caswellsilverite-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Cu1+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with two equivalent GaSe6 octahedra, corners with four equivalent CuSe6 octahedra, edges with four equivalent CuSe6 octahedra, and edges with eight equivalent GaSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Cu–Se bond distances ranging from 2.64–2.67 Å. Ga3+ is bonded to six Se2- atoms to form GaSe6 octahedra that share corners with two equivalent CuSe6 octahedra, corners with four equivalent GaSe6 octahedra, edges with four equivalent GaSe6 octahedra, and edges with eight equivalent CuSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ga–Se bond distances ranging from 2.64–2.67 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Cu1+ and three equivalent Ga3+ atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to three equivalent Cu1+ and three equivalent Ga3+ atoms to form a mixture of edge and corner-sharing SeGa3Cu3 octahedra. The corner-sharing octahedral tilt angles are 0°.