Materials Data on HfCuGe2 by Materials Project
HfCuGe2 is Parent of FeAs superconductors-derived structured and crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Hf is bonded to four equivalent Cu and eight Ge atoms to form distorted HfCu4Ge8 cuboctahedra that share corners with four equivalent HfCu4Ge8 cuboctahedra, edges with eight equivalent HfCu4Ge8 cuboctahedra, edges with eight equivalent CuHf4Cu4Ge4 cuboctahedra, faces with four equivalent HfCu4Ge8 cuboctahedra, and faces with four equivalent CuHf4Cu4Ge4 cuboctahedra. All Hf–Cu bond lengths are 3.06 Å. There are four shorter (2.79 Å) and four longer (2.88 Å) Hf–Ge bond lengths. Cu is bonded to four equivalent Hf, four equivalent Cu, and four equivalent Ge atoms to form distorted CuHf4Cu4Ge4 cuboctahedra that share corners with four equivalent CuHf4Cu4Ge4 cuboctahedra, edges with eight equivalent HfCu4Ge8 cuboctahedra, faces with four equivalent HfCu4Ge8 cuboctahedra, and faces with eight equivalent CuHf4Cu4Ge4 cuboctahedra. All Cu–Cu bond lengths are 2.68 Å. All Cu–Ge bond lengths are 2.49 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 8-coordinate geometry to four equivalent Hf and four equivalent Ge atoms. All Ge–Ge bond lengths are 2.68 Å. In the second Ge site, Ge is bonded in a 8-coordinate geometry to four equivalent Hf and four equivalent Cu atoms.