Materials Data on Er3(CuGe)4 by Materials Project
Er3Cu4Ge4 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Er sites. In the first Er site, Er is bonded in a 12-coordinate geometry to six equivalent Cu and six Ge atoms. There are four shorter (2.98 Å) and two longer (3.04 Å) Er–Cu bond lengths. There are two shorter (2.99 Å) and four longer (3.03 Å) Er–Ge bond lengths. In the second Er site, Er is bonded to six Ge atoms to form distorted edge-sharing ErGe6 octahedra. There are four shorter (2.92 Å) and two longer (2.99 Å) Er–Ge bond lengths. Cu is bonded in a 12-coordinate geometry to three equivalent Er, one Cu, and four Ge atoms. The Cu–Cu bond length is 2.55 Å. There are a spread of Cu–Ge bond distances ranging from 2.49–2.57 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to six Er, two equivalent Cu, and one Ge atom. The Ge–Ge bond length is 2.57 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to three Er and six equivalent Cu atoms.