Ac is alpha La structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ac sites. In the first Ac site, Ac(1) is bonded to six equivalent Ac(1) and six equivalent Ac(2) atoms to form a mixture of edge, face, and corner-sharing AcAc12 cuboctahedra. In the second Ac site, Ac(2) is bonded to six equivalent Ac(1) and six equivalent Ac(2) atoms to form a mixture of edge, face, and corner-sharing AcAc12 cuboctahedra.
Ac is alpha La structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ac sites. In the first Ac site, Ac(1) is bonded to six equivalent Ac(1) and six equivalent Ac(2) atoms to form a mixture of edge, face, and corner-sharing AcAc12 cuboctahedra. All Ac(1)-Ac(1) bond lengths are 4.05 Å. All Ac(1)-Ac(2) bond lengths are 4.01 Å. In the second Ac site, Ac(2) is bonded to six equivalent Ac(1) and six equivalent Ac(2) atoms to form a mixture of edge, face, and corner-sharing AcAc12 cuboctahedra. All Ac(2)-Ac(2) bond lengths are 4.05 Å.