Materials Data on K2(NbBr3)3 by Materials Project

Abstract

K2(NbBr3)3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six Br1- atoms. There are a spread of K–Br bond distances ranging from 3.25–3.93 Å. There are two inequivalent Nb+2.33+ sites. In the first Nb+2.33+ site, Nb+2.33+ is bonded to five Br1- atoms to form distorted corner-sharing NbBr5 square pyramids. There are a spread of Nb–Br bond distances ranging from 2.61–2.89 Å. In the second Nb+2.33+ site, Nb+2.33+ is bonded to five Br1- atoms to form corner-sharing NbBr5 square pyramids. There are a spread of Nb–Br bond distances ranging from 2.62–2.84 Å. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Nb+2.33+ atoms. In the second Br1- site, Br1- is bonded in a trigonal planar geometry to two equivalent K1+ and one Nb+2.33+ atom. In the third Br1- site, Br1- is bonded to three equivalent K1+ and one Nb+2.33+ atom to form a mixture of edge and corner-sharing BrK3Nb tetrahedra. In the fourth Br1- site, Br1- is bonded in a 2-coordinate geometry to two equivalent Nb+2.33+ atoms. In the fifth Br1- site, Br1- is bonded in a 2-coordinate geometry to two Nb+2.33+ atoms. In the sixth Br1- site, Br1- is bonded in a 3-coordinate geometry to one K1+ and two Nb+2.33+ atoms.