Materials Data on Nb3I8 by Materials Project
Nb3I8 crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of six Nb3I8 sheets oriented in the (0, 0, 1) direction. Nb+2.67+ is bonded to six I1- atoms to form distorted edge-sharing NbI6 octahedra. There are a spread of Nb–I bond distances ranging from 2.77–3.07 Å. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Nb+2.67+ atoms. In the second I1- site, I1- is bonded in a 2-coordinate geometry to two equivalent Nb+2.67+ atoms. In the third I1- site, I1- is bonded in a water-like geometry to two equivalent Nb+2.67+ atoms. In the fourth I1- site, I1- is bonded in a 12-coordinate geometry to three equivalent Nb+2.67+ atoms.