Materials Data on Ho3(CuSi)4 by Materials Project
Ho3Cu4Si4 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 6-coordinate geometry to six Si4- atoms. There are two shorter (2.94 Å) and four longer (2.97 Å) Ho–Si bond lengths. In the second Ho3+ site, Ho3+ is bonded to six Si4- atoms to form edge-sharing HoSi6 octahedra. There are four shorter (2.91 Å) and two longer (2.95 Å) Ho–Si bond lengths. Cu+1.75+ is bonded in a 4-coordinate geometry to one Cu+1.75+ and four Si4- atoms. The Cu–Cu bond length is 2.50 Å. There are a spread of Cu–Si bond distances ranging from 2.44–2.56 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to six Ho3+, two equivalent Cu+1.75+, and one Si4- atom. The Si–Si bond length is 2.42 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to three Ho3+ and six equivalent Cu+1.75+ atoms.