Materials Data on Cu8GeSe6 by Materials Project

Abstract

Cu8GeSe6 crystallizes in the hexagonal P6_3cm space group. The structure is three-dimensional. there are five inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a 3-coordinate geometry to four Se2- atoms. There are a spread of Cu–Se bond distances ranging from 2.45–3.10 Å. In the second Cu1+ site, Cu1+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Cu–Se bond distances ranging from 2.45–3.10 Å. In the third Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent GeSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.43–2.65 Å. In the fourth Cu1+ site, Cu1+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of Cu–Se bond distances ranging from 2.38–2.52 Å. In the fifth Cu1+ site, Cu1+ is bonded in a distorted trigonal planar geometry to three Se2- atoms. There are a spread of Cu–Se bond distances ranging from 2.43–2.50 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with three equivalent CuSe4 tetrahedra. All Ge–Se bond lengths are 2.38 Å. In the second Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four Se2- atoms. There are one shorter (2.37 Å) and three longer (2.38 Å) Ge–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a tetrahedral geometry to three equivalent Cu1+ and one Ge4+ atom. In the second Se2- site, Se2- is bonded in a distorted hexagonal planar geometry to six Cu1+ atoms. In the third Se2- site, Se2- is bonded in a 7-coordinate geometry to seven Cu1+ atoms. In the fourth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Cu1+ and one Ge4+ atom. In the fifth Se2- site, Se2- is bonded in a tetrahedral geometry to three equivalent Cu1+ and one Ge4+ atom. In the sixth Se2- site, Se2- is bonded in a distorted pentagonal planar geometry to four Cu1+ and one Ge4+ atom.