Materials Data on GaCuSe2 by Materials Project

Abstract

CuGaSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Cu1+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with six 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 two shorter (2.63 Å) and four longer (2.67 Å) Cu–Se bond lengths. Ga3+ is bonded to six Se2- atoms to form GaSe6 octahedra that share corners with six 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 two shorter (2.63 Å) and four longer (2.67 Å) Ga–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Cu1+ and four equivalent Ga3+ atoms to form a mixture of edge and corner-sharing SeGa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to four equivalent Cu1+ and two equivalent Ga3+ atoms to form SeGa2Cu4 octahedra that share corners with six equivalent SeGa2Cu4 octahedra and edges with twelve SeGa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 0°.