Materials Data on CoCu2GeSe4 by Materials Project

Abstract

Cu2CoGeSe4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. Co2+ is bonded to four Se2- atoms to form CoSe4 tetrahedra that share corners with four equivalent GeSe4 tetrahedra and corners with eight equivalent CuSe4 tetrahedra. There are one shorter (2.36 Å) and three longer (2.39 Å) Co–Se bond lengths. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent CoSe4 tetrahedra, corners with four equivalent CuSe4 tetrahedra, and corners with four equivalent GeSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.40–2.43 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with four equivalent CoSe4 tetrahedra and corners with eight equivalent CuSe4 tetrahedra. There are one shorter (2.44 Å) and three longer (2.47 Å) Ge–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Co2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SeCoCu2Ge tetrahedra. In the second Se2- site, Se2- is bonded to one Co2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SeCoCu2Ge tetrahedra. In the third Se2- site, Se2- is bonded to one Co2+, two equivalent Cu1+, and one Ge4+ atom to form corner-sharing SeCoCu2Ge tetrahedra.