RbSr3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Rb(1) is bonded to four equivalent Sr(2) and eight equivalent Sr(1) atoms to form RbSr12 cuboctahedra that share corners with four equivalent Rb(1)Sr12 cuboctahedra, corners with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, edges with eight equivalent Rb(1)Sr12 cuboctahedra, edges with sixteen equivalent Sr(1)Rb4Sr8 cuboctahedra, faces with four equivalent Rb(1)Sr12 cuboctahedra, faces with six equivalent Sr(2)Rb4Sr8 cuboctahedra, and faces with eight equivalent Sr(1)Rb4Sr8 cuboctahedra. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent Rb(1), four equivalent Sr(1), and four equivalent Sr(2) atoms to form SrRb4Sr8 cuboctahedra that share corners with twelve equivalent Sr(1)Rb4Sr8 cuboctahedra, edges with eight equivalent Rb(1)Sr12 cuboctahedra, edges with eight equivalent Sr(1)Rb4Sr8 cuboctahedra, edges with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, faces with four equivalent Rb(1)Sr12 cuboctahedra, faces with four equivalent Sr(2)Rb4Sr8 cuboctahedra, and faces with ten equivalent Sr(1)Rb4Sr8 cuboctahedra. In the second Sr site, Sr(2) is bonded to four equivalent Rb(1) and eight equivalent Sr(1) atoms to form SrRb4Sr8 cuboctahedra that share corners with four equivalent Sr(2)Rb4Sr8 cuboctahedra, corners with eight equivalent Rb(1)Sr12 cuboctahedra, edges with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, edges with sixteen equivalent Sr(1)Rb4Sr8 cuboctahedra, faces with four equivalent Sr(2)Rb4Sr8 cuboctahedra, faces with six equivalent Rb(1)Sr12 cuboctahedra, and faces with eight equivalent Sr(1)Rb4Sr8 cuboctahedra.
RbSr3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Rb(1) is bonded to four equivalent Sr(2) and eight equivalent Sr(1) atoms to form RbSr12 cuboctahedra that share corners with four equivalent Rb(1)Sr12 cuboctahedra, corners with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, edges with eight equivalent Rb(1)Sr12 cuboctahedra, edges with sixteen equivalent Sr(1)Rb4Sr8 cuboctahedra, faces with four equivalent Rb(1)Sr12 cuboctahedra, faces with six equivalent Sr(2)Rb4Sr8 cuboctahedra, and faces with eight equivalent Sr(1)Rb4Sr8 cuboctahedra. All Rb(1)-Sr(2) bond lengths are 4.37 Å. All Rb(1)-Sr(1) bond lengths are 4.44 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent Rb(1), four equivalent Sr(1), and four equivalent Sr(2) atoms to form SrRb4Sr8 cuboctahedra that share corners with twelve equivalent Sr(1)Rb4Sr8 cuboctahedra, edges with eight equivalent Rb(1)Sr12 cuboctahedra, edges with eight equivalent Sr(1)Rb4Sr8 cuboctahedra, edges with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, faces with four equivalent Rb(1)Sr12 cuboctahedra, faces with four equivalent Sr(2)Rb4Sr8 cuboctahedra, and faces with ten equivalent Sr(1)Rb4Sr8 cuboctahedra. All Sr(1)-Sr(1) bond lengths are 4.37 Å. All Sr(1)-Sr(2) bond lengths are 4.44 Å. In the second Sr site, Sr(2) is bonded to four equivalent Rb(1) and eight equivalent Sr(1) atoms to form SrRb4Sr8 cuboctahedra that share corners with four equivalent Sr(2)Rb4Sr8 cuboctahedra, corners with eight equivalent Rb(1)Sr12 cuboctahedra, edges with eight equivalent Sr(2)Rb4Sr8 cuboctahedra, edges with sixteen equivalent Sr(1)Rb4Sr8 cuboctahedra, faces with four equivalent Sr(2)Rb4Sr8 cuboctahedra, faces with six equivalent Rb(1)Sr12 cuboctahedra, and faces with eight equivalent Sr(1)Rb4Sr8 cuboctahedra.