Materials Data on K3GeSe3 by Materials Project
K3GeSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six Se2- atoms to form a mixture of distorted corner, edge, and face-sharing KSe6 octahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of K–Se bond distances ranging from 3.36–3.70 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.45–3.54 Å. In the third K1+ site, K1+ is bonded to six Se2- atoms to form a mixture of distorted corner, edge, and face-sharing KSe6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 33–68°. There are a spread of K–Se bond distances ranging from 3.29–3.54 Å. Ge3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.39 Å) and one longer (2.40 Å) Ge–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 7-coordinate geometry to six K1+ and one Ge3+ atom. In the second Se2- site, Se2- is bonded in a 7-coordinate geometry to six K1+ and one Ge3+ atom.