Materials Data on Cu2GeSe3 by Materials Project

Abstract

Cu2GeSe3 is Enargite-like structured and crystallizes in the orthorhombic Fdd2 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 five equivalent GeSe4 tetrahedra and corners with seven CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.40–2.44 Å. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with six CuSe4 tetrahedra and corners with six equivalent GeSe4 tetrahedra. There are two shorter (2.41 Å) and two longer (2.44 Å) Cu–Se bond lengths. In the third Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent GeSe4 tetrahedra and corners with eight CuSe4 tetrahedra. All Cu–Se bond lengths are 2.40 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with two equivalent GeSe4 tetrahedra and corners with ten CuSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.41–2.53 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two Cu1+ and two equivalent Ge4+ atoms to form corner-sharing SeCu2Ge2 tetrahedra. In the second Se2- site, Se2- is bonded to three Cu1+ and one Ge4+ atom to form corner-sharing SeCu3Ge tetrahedra. In the third Se2- site, Se2- is bonded to three Cu1+ and one Ge4+ atom to form corner-sharing SeCu3Ge tetrahedra.