Materials Data on Rb2(NbBr3)3 by Materials Project
Rb2(NbBr3)3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Rb1+ is bonded in a 6-coordinate geometry to six Br1- atoms. There are a spread of Rb–Br bond distances ranging from 3.38–3.96 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 corner-sharing NbBr5 square pyramids. There are four shorter (2.62 Å) and one longer (2.84 Å) Nb–Br bond lengths. In the second 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 2.62–2.89 Å. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 2-coordinate geometry to two equivalent Nb+2.33+ atoms. In the second Br1- site, Br1- is bonded in a 2-coordinate geometry to two Nb+2.33+ atoms. In the third Br1- site, Br1- is bonded in a 4-coordinate geometry to two equivalent Rb1+ and two equivalent Nb+2.33+ atoms. In the fourth Br1- site, Br1- is bonded to three equivalent Rb1+ and one Nb+2.33+ atom to form a mixture of distorted edge and corner-sharing BrRb3Nb tetrahedra. In the fifth Br1- site, Br1- is bonded in a 3-coordinate geometry to one Rb1+ and two Nb+2.33+ atoms. In the sixth Br1- site, Br1- is bonded in a trigonal planar geometry to two equivalent Rb1+ and one Nb+2.33+ atom.