Materials Data on Nb4Tl4O13 by Materials Project
Nb4Tl4O13 crystallizes in the cubic F-43m space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six equivalent NbO6 octahedra and edges with six equivalent TlO7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 38°. All Nb–O bond lengths are 2.02 Å. Tl+1.50+ is bonded to seven O2- atoms to form distorted TlO7 hexagonal pyramids that share corners with three equivalent TlO7 hexagonal pyramids, edges with three equivalent TlO7 hexagonal pyramids, and edges with six equivalent NbO6 octahedra. There are a spread of Tl–O bond distances ranging from 2.37–2.80 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ and two equivalent Tl+1.50+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Nb5+ and two equivalent Tl+1.50+ atoms. In the third O2- site, O2- is bonded in a tetrahedral geometry to four equivalent Tl+1.50+ atoms.