Rb2LaBr5 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 8-coordinate geometry to two equivalent Br(1), two equivalent Br(2), two equivalent Br(3), and two equivalent Br(4) atoms. La(1) is bonded to one Br(1), one Br(3), one Br(4), and four equivalent Br(2) atoms to form distorted edge-sharing LaBr7 pentagonal bipyramids. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share  a cornercorner with one Br(4)Rb4La trigonal bipyramid, corners with four equivalent Br(1)Rb4La trigonal bipyramids, corners with five equivalent Br(3)Rb4La trigonal bipyramids, corners with four equivalent Br(2)Rb2La2 trigonal pyramids, edges with two equivalent Br(3)Rb4La trigonal bipyramids, edges with four equivalent Br(4)Rb4La trigonal bipyramids, and edges with four equivalent Br(2)Rb2La2 trigonal pyramids. In the second Br site, Br(2) is bonded to two equivalent Rb(1) and two equivalent La(1) atoms to form distorted BrRb2La2 trigonal pyramids that share corners with two equivalent Br(1)Rb4La trigonal bipyramids, corners with two equivalent Br(4)Rb4La trigonal bipyramids, corners with four equivalent Br(3)Rb4La trigonal bipyramids, corners with six equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(3)Rb4La trigonal bipyramid, edges with two equivalent Br(1)Rb4La trigonal bipyramids, edges with two equivalent Br(4)Rb4La trigonal bipyramids, and  an edgeedge with one Br(2)Rb2La2 trigonal pyramid. In the third Br site, Br(3) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share corners with four equivalent Br(4)Rb4La trigonal bipyramids, corners with five equivalent Br(1)Rb4La trigonal bipyramids, corners with eight equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(4)Rb4La trigonal bipyramid, edges with two equivalent Br(1)Rb4La trigonal bipyramids, edges with two equivalent Br(3)Rb4La trigonal bipyramids, edges with two equivalent Br(2)Rb2La2 trigonal pyramids, and  a faceface with one Br(4)Rb4La trigonal bipyramid. In the fourth Br site, Br(4) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share  a cornercorner with one Br(1)Rb4La trigonal bipyramid, corners with four equivalent Br(3)Rb4La trigonal bipyramids, corners with four equivalent Br(4)Rb4La trigonal bipyramids, corners with four equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(3)Rb4La trigonal bipyramid, edges with four equivalent Br(1)Rb4La trigonal bipyramids, edges with four equivalent Br(2)Rb2La2 trigonal pyramids, and  a faceface with one Br(3)Rb4La trigonal bipyramid.
Rb2LaBr5 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 8-coordinate geometry to two equivalent Br(1), two equivalent Br(2), two equivalent Br(3), and two equivalent Br(4) atoms. There is one shorter (3.54 Å) and one longer (3.62 Å) Rb(1)-Br(1) bond length. There is one shorter (3.64 Å) and one longer (3.66 Å) Rb(1)-Br(2) bond length. There is one shorter (3.44 Å) and one longer (3.49 Å) Rb(1)-Br(3) bond length. There is one shorter (3.45 Å) and one longer (3.48 Å) Rb(1)-Br(4) bond length. La(1) is bonded to one Br(1), one Br(3), one Br(4), and four equivalent Br(2) atoms to form distorted edge-sharing LaBr7 pentagonal bipyramids. The La(1)-Br(1) bond length is 2.97 Å. The La(1)-Br(3) bond length is 3.00 Å. The La(1)-Br(4) bond length is 2.99 Å. There are two shorter (3.05 Å) and two longer (3.07 Å) La(1)-Br(2) bond lengths. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share  a cornercorner with one Br(4)Rb4La trigonal bipyramid, corners with four equivalent Br(1)Rb4La trigonal bipyramids, corners with five equivalent Br(3)Rb4La trigonal bipyramids, corners with four equivalent Br(2)Rb2La2 trigonal pyramids, edges with two equivalent Br(3)Rb4La trigonal bipyramids, edges with four equivalent Br(4)Rb4La trigonal bipyramids, and edges with four equivalent Br(2)Rb2La2 trigonal pyramids. In the second Br site, Br(2) is bonded to two equivalent Rb(1) and two equivalent La(1) atoms to form distorted BrRb2La2 trigonal pyramids that share corners with two equivalent Br(1)Rb4La trigonal bipyramids, corners with two equivalent Br(4)Rb4La trigonal bipyramids, corners with four equivalent Br(3)Rb4La trigonal bipyramids, corners with six equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(3)Rb4La trigonal bipyramid, edges with two equivalent Br(1)Rb4La trigonal bipyramids, edges with two equivalent Br(4)Rb4La trigonal bipyramids, and  an edgeedge with one Br(2)Rb2La2 trigonal pyramid. In the third Br site, Br(3) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share corners with four equivalent Br(4)Rb4La trigonal bipyramids, corners with five equivalent Br(1)Rb4La trigonal bipyramids, corners with eight equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(4)Rb4La trigonal bipyramid, edges with two equivalent Br(1)Rb4La trigonal bipyramids, edges with two equivalent Br(3)Rb4La trigonal bipyramids, edges with two equivalent Br(2)Rb2La2 trigonal pyramids, and  a faceface with one Br(4)Rb4La trigonal bipyramid. In the fourth Br site, Br(4) is bonded to four equivalent Rb(1) and one La(1) atom to form distorted BrRb4La trigonal bipyramids that share  a cornercorner with one Br(1)Rb4La trigonal bipyramid, corners with four equivalent Br(3)Rb4La trigonal bipyramids, corners with four equivalent Br(4)Rb4La trigonal bipyramids, corners with four equivalent Br(2)Rb2La2 trigonal pyramids,  an edgeedge with one Br(3)Rb4La trigonal bipyramid, edges with four equivalent Br(1)Rb4La trigonal bipyramids, edges with four equivalent Br(2)Rb2La2 trigonal pyramids, and  a faceface with one Br(3)Rb4La trigonal bipyramid.