Materials Data on Rb3Sb2Br9 by Materials Project
Rb3Sb2Br9 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve Br1- atoms to form RbBr12 cuboctahedra that share corners with twelve RbBr12 cuboctahedra, faces with six equivalent RbBr12 cuboctahedra, and faces with six equivalent SbBr6 octahedra. There are six shorter (4.03 Å) and six longer (4.09 Å) Rb–Br bond lengths. In the second Rb1+ site, Rb1+ is bonded to twelve Br1- atoms to form RbBr12 cuboctahedra that share corners with twelve RbBr12 cuboctahedra, faces with six RbBr12 cuboctahedra, and faces with five equivalent SbBr6 octahedra. There are a spread of Rb–Br bond distances ranging from 3.94–4.03 Å. Sb3+ is bonded to six Br1- atoms to form SbBr6 octahedra that share corners with three equivalent SbBr6 octahedra and faces with eight RbBr12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.69 Å) and three longer (2.96 Å) Sb–Br bond lengths. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted single-bond geometry to four Rb1+ and one Sb3+ atom. In the second Br1- site, Br1- is bonded to four Rb1+ and two equivalent Sb3+ atoms to form a mixture of distorted corner and face-sharing BrRb4Sb2 octahedra. The corner-sharing octahedra tilt angles range from 0–60°.