Materials Data on Tb3CuGeSe7 by Materials Project
Tb3CuGeSe7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Tb3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Tb–Se bond distances ranging from 2.88–3.35 Å. Cu1+ is bonded in a trigonal planar geometry to three equivalent Se2- atoms. All Cu–Se bond lengths are 2.38 Å. Ge4+ is bonded in a tetrahedral geometry to four Se2- atoms. There are one shorter (2.36 Å) and three longer (2.40 Å) Ge–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Tb3+ and one Cu1+ atom. In the second Se2- site, Se2- is bonded in a tetrahedral geometry to three equivalent Tb3+ and one Ge4+ atom. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Tb3+ and one Ge4+ atom.