Materials Data on TlCu7Se4 by Materials Project

Abstract

TlCu7Se4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are seven inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.44 Å) and two longer (2.53 Å) Cu–Se bond lengths. In the second Cu1+ site, Cu1+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.37 Å) and two longer (2.52 Å) Cu–Se bond lengths. In the third Cu1+ site, Cu1+ is bonded in a trigonal planar geometry to three Se2- atoms. There are two shorter (2.46 Å) and one longer (2.49 Å) Cu–Se bond lengths. In the fourth Cu1+ site, Cu1+ is bonded in a distorted trigonal planar geometry to three Se2- atoms. There are one shorter (2.43 Å) and two longer (2.56 Å) Cu–Se bond lengths. In the fifth Cu1+ site, Cu1+ is bonded to four Se2- atoms to form distorted corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.41–2.62 Å. In the sixth Cu1+ site, Cu1+ is bonded to four Se2- atoms to form a mixture of distorted edge and corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.49–2.65 Å. In the seventh Cu1+ site, Cu1+ is bonded to four Se2- atoms to form a mixture of distorted edge and corner-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.44–2.65 Å. Tl1+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are a spread of Tl–Se bond distances ranging from 3.34–3.43 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 8-coordinate geometry to six Cu1+ and two equivalent Tl1+ atoms. In the second Se2- site, Se2- is bonded in a 7-coordinate geometry to five Cu1+ and two equivalent Tl1+ atoms. In the third Se2- site, Se2- is bonded in a 9-coordinate geometry to seven Cu1+ and two equivalent Tl1+ atoms. In the fourth Se2- site, Se2- is bonded in a 8-coordinate geometry to six Cu1+ and two equivalent Tl1+ atoms.