Materials Data on ScCuSe2 by Materials Project
ScCuSe2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six Se2- atoms to form ScSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with six ScSe6 octahedra, and edges with three CuSe4 tetrahedra. There are a spread of Sc–Se bond distances ranging from 2.67–2.78 Å. In the second Sc3+ site, Sc3+ is bonded to six Se2- atoms to form ScSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with six ScSe6 octahedra, and edges with three CuSe4 tetrahedra. There are a spread of Sc–Se bond distances ranging from 2.68–2.78 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with six ScSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, edges with three ScSe6 octahedra, and an edgeedge with one CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 14–60°. There are a spread of Cu–Se bond distances ranging from 2.43–2.46 Å. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with six ScSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, edges with three ScSe6 octahedra, and an edgeedge with one CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–60°. There are three shorter (2.43 Å) and one longer (2.47 Å) Cu–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Sc3+ and two Cu1+ atoms to form a mixture of distorted edge and corner-sharing SeSc3Cu2 square pyramids. In the second Se2- site, Se2- is bonded to three Sc3+ and two Cu1+ atoms to form a mixture of edge and corner-sharing SeSc3Cu2 square pyramids. In the third Se2- site, Se2- is bonded to three Sc3+ and two Cu1+ atoms to form a mixture of edge and corner-sharing SeSc3Cu2 square pyramids. In the fourth Se2- site, Se2- is bonded to three Sc3+ and two Cu1+ atoms to form a mixture of distorted edge and corner-sharing SeSc3Cu2 square pyramids.