Rb2CuBrCl3 is (La,Ba)CuO4-derived structured and crystallizes in the orthorhombic Aea2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to four equivalent Br(1), one Cl(1), and four equivalent Cl(2) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one Br(1), four equivalent Cl(1), and four equivalent Cl(2) atoms. Cu(1) is bonded to one Br(1), one Cl(1), and four equivalent Cl(2) atoms to form corner-sharing CuBrCl5 octahedra. The corner-sharing octahedral tilt angles are 2°. Br(1) is bonded to one Rb(2), four equivalent Rb(1), and one Cu(1) atom to form distorted BrRb5Cu octahedra that share  a cornercorner with one Cl(1)Rb5Cu octahedra, corners with four equivalent Br(1)Rb5Cu octahedra, corners with twelve equivalent Cl(2)Rb4Cu2 octahedra, edges with four equivalent Br(1)Rb5Cu octahedra, edges with four equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Rb(1), four equivalent Rb(2), and one Cu(1) atom to form distorted ClRb5Cu octahedra that share  a cornercorner with one Br(1)Rb5Cu octahedra, corners with four equivalent Cl(1)Rb5Cu octahedra, corners with twelve equivalent Cl(2)Rb4Cu2 octahedra, edges with four equivalent Br(1)Rb5Cu octahedra, edges with four equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. In the second Cl site, Cl(2) is bonded to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Cu(1) atoms to form distorted ClRb4Cu2 octahedra that share corners with two equivalent Cl(2)Rb4Cu2 octahedra, corners with six equivalent Br(1)Rb5Cu octahedra, corners with six equivalent Cl(1)Rb5Cu octahedra, edges with two equivalent Cl(2)Rb4Cu2 octahedra, faces with two equivalent Br(1)Rb5Cu octahedra, faces with two equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 2-59°.
Rb2CuBrCl3 is (La,Ba)CuO4-derived structured and crystallizes in the orthorhombic Aea2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to four equivalent Br(1), one Cl(1), and four equivalent Cl(2) atoms. All Rb(1)-Br(1) bond lengths are 3.66 Å. The Rb(1)-Cl(1) bond length is 3.47 Å. All Rb(1)-Cl(2) bond lengths are 3.43 Å. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one Br(1), four equivalent Cl(1), and four equivalent Cl(2) atoms. The Rb(2)-Br(1) bond length is 3.45 Å. All Rb(2)-Cl(1) bond lengths are 3.66 Å. There are two shorter (3.37 Å) and two longer (3.38 Å) Rb(2)-Cl(2) bond lengths. Cu(1) is bonded to one Br(1), one Cl(1), and four equivalent Cl(2) atoms to form corner-sharing CuBrCl5 octahedra. The corner-sharing octahedral tilt angles are 2°. The Cu(1)-Br(1) bond length is 2.55 Å. The Cu(1)-Cl(1) bond length is 2.36 Å. There are two shorter (2.27 Å) and two longer (2.90 Å) Cu(1)-Cl(2) bond lengths. Br(1) is bonded to one Rb(2), four equivalent Rb(1), and one Cu(1) atom to form distorted BrRb5Cu octahedra that share  a cornercorner with one Cl(1)Rb5Cu octahedra, corners with four equivalent Br(1)Rb5Cu octahedra, corners with twelve equivalent Cl(2)Rb4Cu2 octahedra, edges with four equivalent Br(1)Rb5Cu octahedra, edges with four equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one Rb(1), four equivalent Rb(2), and one Cu(1) atom to form distorted ClRb5Cu octahedra that share  a cornercorner with one Br(1)Rb5Cu octahedra, corners with four equivalent Cl(1)Rb5Cu octahedra, corners with twelve equivalent Cl(2)Rb4Cu2 octahedra, edges with four equivalent Br(1)Rb5Cu octahedra, edges with four equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. In the second Cl site, Cl(2) is bonded to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Cu(1) atoms to form distorted ClRb4Cu2 octahedra that share corners with two equivalent Cl(2)Rb4Cu2 octahedra, corners with six equivalent Br(1)Rb5Cu octahedra, corners with six equivalent Cl(1)Rb5Cu octahedra, edges with two equivalent Cl(2)Rb4Cu2 octahedra, faces with two equivalent Br(1)Rb5Cu octahedra, faces with two equivalent Cl(1)Rb5Cu octahedra, and faces with four equivalent Cl(2)Rb4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 2-59°.