Materials Data on CsNb6I11 by Materials Project
CsNb6I11 crystallizes in the hexagonal P6_322 space group. The structure is three-dimensional. Cs is bonded to twelve I atoms to form CsI12 cuboctahedra that share corners with twelve equivalent NbI5 square pyramids, faces with two equivalent CsI12 cuboctahedra, and faces with six equivalent NbI5 square pyramids. There are six shorter (4.26 Å) and six longer (4.42 Å) Cs–I bond lengths. Nb is bonded to five I atoms to form distorted NbI5 square pyramids that share corners with two equivalent CsI12 cuboctahedra, a cornercorner with one NbI5 square pyramid, edges with four equivalent NbI5 square pyramids, and a faceface with one CsI12 cuboctahedra. There are a spread of Nb–I bond distances ranging from 2.87–3.07 Å. There are three inequivalent I sites. In the first I site, I is bonded in a 4-coordinate geometry to one Cs and three equivalent Nb atoms. In the second I site, I is bonded in a distorted bent 120 degrees geometry to two equivalent Cs and two equivalent Nb atoms. In the third I site, I is bonded in a 3-coordinate geometry to three equivalent Nb atoms.