Materials Data on Er3CuGeS7 by Materials Project
Er3CuGeS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Er3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Er–S bond distances ranging from 2.72–3.34 Å. Cu1+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All Cu–S bond lengths are 2.23 Å. Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.21 Å) and three longer (2.24 Å) Ge–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Er3+ and one Ge4+ atom. In the second S2- site, S2- is bonded in a 4-coordinate geometry to four equivalent Er3+ and one Cu1+ atom. In the third S2- site, S2- is bonded in a distorted tetrahedral geometry to three equivalent Er3+ and one Ge4+ atom.