Tm3Ho is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Tm(1) is bonded to eight equivalent Tm(1) and four equivalent Ho(1) atoms to form TmHo4Tm8 cuboctahedra that share corners with four equivalent Ho(1)Tm12 cuboctahedra, corners with fourteen equivalent Tm(1)Ho4Tm8 cuboctahedra, edges with six equivalent Ho(1)Tm12 cuboctahedra, edges with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra, faces with four equivalent Ho(1)Tm12 cuboctahedra, and faces with sixteen equivalent Tm(1)Ho4Tm8 cuboctahedra. Ho(1) is bonded to twelve equivalent Tm(1) atoms to form HoTm12 cuboctahedra that share corners with six equivalent Ho(1)Tm12 cuboctahedra, corners with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra, edges with eighteen equivalent Tm(1)Ho4Tm8 cuboctahedra, faces with eight equivalent Ho(1)Tm12 cuboctahedra, and faces with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra.
Tm3Ho is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Tm(1) is bonded to eight equivalent Tm(1) and four equivalent Ho(1) atoms to form TmHo4Tm8 cuboctahedra that share corners with four equivalent Ho(1)Tm12 cuboctahedra, corners with fourteen equivalent Tm(1)Ho4Tm8 cuboctahedra, edges with six equivalent Ho(1)Tm12 cuboctahedra, edges with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra, faces with four equivalent Ho(1)Tm12 cuboctahedra, and faces with sixteen equivalent Tm(1)Ho4Tm8 cuboctahedra. There are a spread of Tm(1)-Tm(1) bond distances ranging from 3.50-3.55 Å. There are two shorter (3.51 Å) and two longer (3.54 Å) Tm(1)-Ho(1) bond lengths. Ho(1) is bonded to twelve equivalent Tm(1) atoms to form HoTm12 cuboctahedra that share corners with six equivalent Ho(1)Tm12 cuboctahedra, corners with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra, edges with eighteen equivalent Tm(1)Ho4Tm8 cuboctahedra, faces with eight equivalent Ho(1)Tm12 cuboctahedra, and faces with twelve equivalent Tm(1)Ho4Tm8 cuboctahedra.