Materials Data on BaCu6Te6S by Materials Project
BaCu6Te6S 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 CuTe3S tetrahedra, edges with six equivalent BaTe12 cuboctahedra, and faces with six CuTe3S tetrahedra. There are a spread of Ba–Te bond distances ranging from 3.74–3.81 Å. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to three Te1- and one S2- atom to form CuTe3S tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with eight CuTe3S tetrahedra, an edgeedge with one CuTe3S 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–S bond length is 2.32 Å. In the second Cu1+ site, Cu1+ is bonded to three Te1- and one S2- atom to form CuTe3S tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with eight CuTe3S tetrahedra, edges with two equivalent CuTe3S 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–S bond length is 2.30 Å. In the third Cu1+ site, Cu1+ is bonded to three Te1- and one S2- atom to form CuTe3S tetrahedra that share corners with three equivalent BaTe12 cuboctahedra, corners with six CuTe3S tetrahedra, edges with three CuTe3S tetrahedra, and a faceface with one BaTe12 cuboctahedra. There are a spread of Cu–Te bond distances ranging from 2.60–2.65 Å. The Cu–S bond length is 2.42 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 2.83 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. S2- is bonded in a 6-coordinate geometry to six Cu1+ atoms.