Materials Data on BaCu6Te6Se by Materials Project
BaCu6Te6Se crystallizes in the monoclinic P2 space group. The structure is three-dimensional. Ba2+ is bonded to twelve Te1- atoms to form BaTe12 cuboctahedra that share corners with eighteen CuTe3Se tetrahedra, edges with six equivalent BaTe12 cuboctahedra, and faces with six CuTe3Se tetrahedra. There are a spread of Ba–Te bond distances ranging from 3.76–3.83 Å. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to three Te1- and one Se2- atom to form CuTe3Se tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with eight CuTe3Se tetrahedra, an edgeedge with one CuTe3Se tetrahedra, and a faceface with one BaTe12 cuboctahedra. There are a spread of Cu–Te bond distances ranging from 2.58–2.65 Å. The Cu–Se bond length is 2.42 Å. In the second Cu1+ site, Cu1+ is bonded to three Te1- and one Se2- atom to form CuTe3Se tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with eight CuTe3Se tetrahedra, edges with two equivalent CuTe3Se tetrahedra, and a faceface with one BaTe12 cuboctahedra. There are a spread of Cu–Te bond distances ranging from 2.59–2.68 Å. The Cu–Se bond length is 2.40 Å. In the third Cu1+ site, Cu1+ is bonded to three Te1- and one Se2- atom to form CuTe3Se tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with six CuTe3Se tetrahedra, edges with three CuTe3Se tetrahedra, and a faceface with one BaTe12 cuboctahedra. There are a spread of Cu–Te bond distances ranging from 2.59–2.65 Å. The Cu–Se bond length is 2.52 Å. There are four inequivalent Te1- sites. In the first Te1- site, Te1- is bonded in a distorted bent 150 degrees geometry to two equivalent Ba2+, two equivalent Cu1+, and one Te1- atom. The Te–Te bond length is 2.82 Å. In the second Te1- site, Te1- is bonded in a 7-coordinate geometry to two equivalent Ba2+, four Cu1+, and one Te1- atom. In the third Te1- site, Te1- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Cu1+ atoms. In the fourth Te1- site, Te1- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and three Cu1+ atoms. Se2- is bonded in a 6-coordinate geometry to six Cu1+ atoms.