Materials Data on Hf4CuSi4 by Materials Project
Hf4CuSi4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 5-coordinate geometry to one Cu and seven Si atoms. The Hf–Cu bond length is 3.11 Å. There are a spread of Hf–Si bond distances ranging from 2.68–2.88 Å. In the second Hf site, Hf is bonded in a 9-coordinate geometry to three equivalent Cu and six Si atoms. There are two shorter (3.03 Å) and one longer (3.14 Å) Hf–Cu bond lengths. There are a spread of Hf–Si bond distances ranging from 2.71–2.81 Å. Cu is bonded to eight Hf and four equivalent Si atoms to form a mixture of edge and face-sharing CuHf8Si4 cuboctahedra. All Cu–Si bond lengths are 2.38 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to seven Hf and two Si atoms. There are one shorter (2.42 Å) and one longer (2.43 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to six Hf, two equivalent Cu, and one Si atom.