Materials Data on Nb3Pb2(O2F)4 by Materials Project
Nb3Pb2(O2F)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Nb+4.67+ sites. In the first Nb+4.67+ site, Nb+4.67+ is bonded to five O2- and one F1- atom to form distorted corner-sharing NbO5F octahedra. The corner-sharing octahedra tilt angles range from 0–21°. There is one shorter (1.86 Å) and four longer (2.00 Å) Nb–O bond length. The Nb–F bond length is 2.26 Å. In the second Nb+4.67+ site, Nb+4.67+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.97 Å) and two longer (2.04 Å) Nb–O bond lengths. Pb3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.52 Å) and four longer (2.84 Å) Pb–F bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Nb+4.67+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Nb+4.67+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two Nb+4.67+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Nb+4.67+ atoms. Both O–Nb bond lengths are 1.97 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Nb+4.67+ and four equivalent Pb3+ atoms. In the second F1- site, F1- is bonded to four equivalent Pb3+ atoms to form a mixture of corner and edge-sharing FPb4 tetrahedra.