DOE OSTI2020
CuInSe2 is Caswellsilverite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with two equivalent InSe6 octahedra, corners with four equivalent CuSe6 octahedra, edges with four equivalent CuSe6 octahedra, and edges with eight InSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Cu–Se bond distances ranging from 2.58–2.81 Å. In the second Cu1+ site, Cu1+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with two equivalent InSe6 octahedra, corners with four equivalent CuSe6 octahedra, edges with four equivalent CuSe6 octahedra, and edges with eight InSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Cu–Se bond distances ranging from 2.58–2.83 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with two equivalent CuSe6 octahedra, corners with four equivalent InSe6 octahedra, edges with four equivalent InSe6 octahedra, and edges with eight CuSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of In–Se bond distances ranging from 2.78–2.86 Å. In the second In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with two equivalent CuSe6 octahedra, corners with four equivalent InSe6 octahedra, edges with four equivalent InSe6 octahedra, and edges with eight CuSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of In–Se bond distances ranging from 2.78–2.86 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Cu1+ and three In3+ atoms to form a mixture of corner and edge-sharing SeIn3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. In the second Se2- site, Se2- is bonded to three Cu1+ and three In3+ atoms to form a mixture of corner and edge-sharing SeIn3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the third Se2- site, Se2- is bonded to three Cu1+ and three In3+ atoms to form a mixture of corner and edge-sharing SeIn3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fourth Se2- site, Se2- is bonded to three Cu1+ and three In3+ atoms to form a mixture of corner and edge-sharing SeIn3Cu3 octahedra. The corner-sharing octahedra tilt angles range from 0–5°.