Rb3Ac is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Rb(1) is bonded to eight equivalent Rb(1) and four equivalent Ac(1) atoms to form RbRb8Ac4 cuboctahedra that share corners with four equivalent Ac(1)Rb12 cuboctahedra, corners with fourteen equivalent Rb(1)Rb8Ac4 cuboctahedra, edges with six equivalent Ac(1)Rb12 cuboctahedra, edges with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra, faces with four equivalent Ac(1)Rb12 cuboctahedra, and faces with sixteen equivalent Rb(1)Rb8Ac4 cuboctahedra. Ac(1) is bonded to twelve equivalent Rb(1) atoms to form AcRb12 cuboctahedra that share corners with six equivalent Ac(1)Rb12 cuboctahedra, corners with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra, edges with eighteen equivalent Rb(1)Rb8Ac4 cuboctahedra, faces with eight equivalent Ac(1)Rb12 cuboctahedra, and faces with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra.
Rb3Ac is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Rb(1) is bonded to eight equivalent Rb(1) and four equivalent Ac(1) atoms to form RbRb8Ac4 cuboctahedra that share corners with four equivalent Ac(1)Rb12 cuboctahedra, corners with fourteen equivalent Rb(1)Rb8Ac4 cuboctahedra, edges with six equivalent Ac(1)Rb12 cuboctahedra, edges with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra, faces with four equivalent Ac(1)Rb12 cuboctahedra, and faces with sixteen equivalent Rb(1)Rb8Ac4 cuboctahedra. There are a spread of Rb(1)-Rb(1) bond distances ranging from 4.55-4.76 Å. There are two shorter (4.65 Å) and two longer (4.67 Å) Rb(1)-Ac(1) bond lengths. Ac(1) is bonded to twelve equivalent Rb(1) atoms to form AcRb12 cuboctahedra that share corners with six equivalent Ac(1)Rb12 cuboctahedra, corners with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra, edges with eighteen equivalent Rb(1)Rb8Ac4 cuboctahedra, faces with eight equivalent Ac(1)Rb12 cuboctahedra, and faces with twelve equivalent Rb(1)Rb8Ac4 cuboctahedra.