Materials Data on Nb3O2F5 by Materials Project
Nb3O2F5 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Nb3+ sites. In the first Nb3+ site, Nb3+ is bonded to two equivalent O2- and four F1- atoms to form edge-sharing NbO2F4 octahedra. Both Nb–O bond lengths are 2.03 Å. There are a spread of Nb–F bond distances ranging from 2.14–2.29 Å. In the second Nb3+ site, Nb3+ is bonded to two equivalent O2- and four F1- atoms to form a mixture of corner and edge-sharing NbO2F4 octahedra. The corner-sharing octahedral tilt angles are 14°. There are one shorter (2.04 Å) and one longer (2.10 Å) Nb–O bond lengths. There are a spread of Nb–F bond distances ranging from 2.09–2.27 Å. O2- is bonded in a 3-coordinate geometry to three Nb3+ atoms. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a water-like geometry to two equivalent Nb3+ atoms. In the second F1- site, F1- is bonded in a 3-coordinate geometry to three Nb3+ atoms. In the third F1- site, F1- is bonded in a 3-coordinate geometry to three Nb3+ atoms. In the fourth F1- site, F1- is bonded in a distorted L-shaped geometry to two equivalent Nb3+ atoms. In the fifth F1- site, F1- is bonded in a water-like geometry to two equivalent Nb3+ atoms.