Materials Data on Rb2AgBr3 by Materials Project

Abstract

Rb2AgBr3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to seven Br1- atoms to form distorted RbBr7 pentagonal bipyramids that share corners with seven RbBr7 pentagonal bipyramids, edges with seven RbBr7 pentagonal bipyramids, edges with four equivalent AgBr4 tetrahedra, and faces with two equivalent RbBr7 pentagonal bipyramids. There are a spread of Rb–Br bond distances ranging from 3.52–3.67 Å. In the second Rb1+ site, Rb1+ is bonded to seven Br1- atoms to form distorted RbBr7 pentagonal bipyramids that share corners with three equivalent RbBr7 pentagonal bipyramids, corners with four equivalent AgBr4 tetrahedra, edges with eleven RbBr7 pentagonal bipyramids, and edges with three equivalent AgBr4 tetrahedra. There are a spread of Rb–Br bond distances ranging from 3.44–3.70 Å. Ag1+ is bonded to four Br1- atoms to form AgBr4 tetrahedra that share corners with four equivalent RbBr7 pentagonal bipyramids, corners with two equivalent AgBr4 tetrahedra, and edges with seven RbBr7 pentagonal bipyramids. There are a spread of Ag–Br bond distances ranging from 2.73–2.76 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded to five Rb1+ and one Ag1+ atom to form a mixture of distorted edge, corner, and face-sharing BrRb5Ag octahedra. The corner-sharing octahedra tilt angles range from 53–55°. In the second Br1- site, Br1- is bonded to five Rb1+ and one Ag1+ atom to form a mixture of distorted edge, corner, and face-sharing BrRb5Ag octahedra. The corner-sharing octahedra tilt angles range from 24–55°. In the third Br1- site, Br1- is bonded in a 6-coordinate geometry to four Rb1+ and two equivalent Ag1+ atoms.