Rb2BaBr4 crystallizes in the tetragonal I-42d space group. Rb(1) is bonded in a 8-coordinate geometry to eight equivalent Br(1) atoms. Ba(1) is bonded to eight equivalent Br(1) atoms to form distorted edge-sharing BaBr8 hexagonal bipyramids. Br(1) is bonded to four equivalent Rb(1) and two equivalent Ba(1) atoms to form a mixture of distorted corner, edge, and face-sharing BrRb4Ba2 octahedra. The corner-sharing octahedral tilt angles range from 15-53°.
Rb2BaBr4 crystallizes in the tetragonal I-42d space group. Rb(1) is bonded in a 8-coordinate geometry to eight equivalent Br(1) atoms. There are a spread of Rb(1)-Br(1) bond distances ranging from 3.37-3.65 Å. Ba(1) is bonded to eight equivalent Br(1) atoms to form distorted edge-sharing BaBr8 hexagonal bipyramids. There are four shorter (3.31 Å) and four longer (3.55 Å) Ba(1)-Br(1) bond lengths. Br(1) is bonded to four equivalent Rb(1) and two equivalent Ba(1) atoms to form a mixture of distorted corner, edge, and face-sharing BrRb4Ba2 octahedra. The corner-sharing octahedral tilt angles range from 15-53°.