Materials Data on Cu3AsSe4 by Materials Project
Cu3AsSe4 is Lavarevi\'{c}ite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent AsSe4 tetrahedra and corners with eight CuSe4 tetrahedra. There are one shorter (2.39 Å) and three longer (2.40 Å) Cu–Se bond lengths. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent AsSe4 tetrahedra and corners with eight CuSe4 tetrahedra. All Cu–Se bond lengths are 2.40 Å. In the third Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent AsSe4 tetrahedra and corners with eight CuSe4 tetrahedra. There are three shorter (2.42 Å) and one longer (2.43 Å) Cu–Se bond lengths. As5+ is bonded to four Se2- atoms to form AsSe4 tetrahedra that share corners with twelve CuSe4 tetrahedra. There are two shorter (2.49 Å) and two longer (2.50 Å) As–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Cu1+ and one As5+ atom to form corner-sharing SeCu3As tetrahedra. In the second Se2- site, Se2- is bonded to three Cu1+ and one As5+ atom to form corner-sharing SeCu3As tetrahedra. In the third Se2- site, Se2- is bonded to three Cu1+ and one As5+ atom to form corner-sharing SeCu3As tetrahedra. In the fourth Se2- site, Se2- is bonded to three Cu1+ and one As5+ atom to form corner-sharing SeCu3As tetrahedra.