Materials Data on Ac3Tm by Materials Project
Ac3Tm is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Ac sites. In the first Ac site, Ac is bonded to eight Ac and four equivalent Tm atoms to form AcAc8Tm4 cuboctahedra that share corners with twelve equivalent AcAc8Tm4 cuboctahedra, edges with eight equivalent TmAc12 cuboctahedra, edges with sixteen AcAc8Tm4 cuboctahedra, faces with four equivalent TmAc12 cuboctahedra, and faces with fourteen AcAc8Tm4 cuboctahedra. There are four shorter (3.86 Å) and four longer (3.88 Å) Ac–Ac bond lengths. All Ac–Tm bond lengths are 3.86 Å. In the second Ac site, Ac is bonded to eight equivalent Ac and four equivalent Tm atoms to form AcAc8Tm4 cuboctahedra that share corners with four equivalent AcAc8Tm4 cuboctahedra, corners with eight equivalent TmAc12 cuboctahedra, edges with twenty-four AcAc8Tm4 cuboctahedra, faces with six equivalent TmAc12 cuboctahedra, and faces with twelve AcAc8Tm4 cuboctahedra. All Ac–Tm bond lengths are 3.88 Å. Tm is bonded to twelve Ac atoms to form TmAc12 cuboctahedra that share corners with four equivalent TmAc12 cuboctahedra, corners with eight equivalent AcAc8Tm4 cuboctahedra, edges with eight equivalent TmAc12 cuboctahedra, edges with sixteen equivalent AcAc8Tm4 cuboctahedra, faces with four equivalent TmAc12 cuboctahedra, and faces with fourteen AcAc8Tm4 cuboctahedra.