Materials Data on CaAc3 by Materials Project
CaAc3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ca is bonded to twelve equivalent Ac atoms to form CaAc12 cuboctahedra that share corners with six equivalent CaAc12 cuboctahedra, corners with twelve equivalent AcCa4Ac8 cuboctahedra, edges with eighteen equivalent AcCa4Ac8 cuboctahedra, faces with eight equivalent CaAc12 cuboctahedra, and faces with twelve equivalent AcCa4Ac8 cuboctahedra. There are six shorter (3.95 Å) and six longer (4.00 Å) Ca–Ac bond lengths. Ac is bonded to four equivalent Ca and eight equivalent Ac atoms to form AcCa4Ac8 cuboctahedra that share corners with four equivalent CaAc12 cuboctahedra, corners with fourteen equivalent AcCa4Ac8 cuboctahedra, edges with six equivalent CaAc12 cuboctahedra, edges with twelve equivalent AcCa4Ac8 cuboctahedra, faces with four equivalent CaAc12 cuboctahedra, and faces with sixteen equivalent AcCa4Ac8 cuboctahedra. There are a spread of Ac–Ac bond distances ranging from 3.96–4.01 Å.