Materials Data on NbBi4BrO8 by Materials Project

Abstract

Bi4NbO8Br crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 30–32°. There are a spread of Nb–O bond distances ranging from 1.88–2.23 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.75 Å. In the second Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four equivalent Br1- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.32 Å. There are a spread of Bi–Br bond distances ranging from 3.47–3.63 Å. In the third Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.25–2.86 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four equivalent Br1- atoms. There are three shorter (2.24 Å) and one longer (2.33 Å) Bi–O bond lengths. There are a spread of Bi–Br bond distances ranging from 3.50–3.61 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Bi3+ atoms to form distorted edge-sharing OBi4 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Nb5+ and two Bi3+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Nb5+ and two Bi3+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ and one Bi3+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ and one Bi3+ atom. In the seventh O2- site, O2- is bonded to four Bi3+ atoms to form distorted edge-sharing OBi4 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. Br1- is bonded in a distorted body-centered cubic geometry to eight Bi3+ atoms.