NpHo3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Np(1) is bonded to twelve equivalent Ho(1) atoms to form NpHo12 cuboctahedra that share corners with six equivalent Np(1)Ho12 cuboctahedra, corners with twelve equivalent Ho(1)Ho8Np4 cuboctahedra, edges with eighteen equivalent Ho(1)Ho8Np4 cuboctahedra, faces with eight equivalent Np(1)Ho12 cuboctahedra, and faces with twelve equivalent Ho(1)Ho8Np4 cuboctahedra. Ho(1) is bonded to four equivalent Np(1) and eight equivalent Ho(1) atoms to form HoHo8Np4 cuboctahedra that share corners with four equivalent Np(1)Ho12 cuboctahedra, corners with fourteen equivalent Ho(1)Ho8Np4 cuboctahedra, edges with six equivalent Np(1)Ho12 cuboctahedra, edges with twelve equivalent Ho(1)Ho8Np4 cuboctahedra, faces with four equivalent Np(1)Ho12 cuboctahedra, and faces with sixteen equivalent Ho(1)Ho8Np4 cuboctahedra.
NpHo3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Np(1) is bonded to twelve equivalent Ho(1) atoms to form NpHo12 cuboctahedra that share corners with six equivalent Np(1)Ho12 cuboctahedra, corners with twelve equivalent Ho(1)Ho8Np4 cuboctahedra, edges with eighteen equivalent Ho(1)Ho8Np4 cuboctahedra, faces with eight equivalent Np(1)Ho12 cuboctahedra, and faces with twelve equivalent Ho(1)Ho8Np4 cuboctahedra. There are six shorter (3.45 Å) and six longer (3.51 Å) Np(1)-Ho(1) bond lengths. Ho(1) is bonded to four equivalent Np(1) and eight equivalent Ho(1) atoms to form HoHo8Np4 cuboctahedra that share corners with four equivalent Np(1)Ho12 cuboctahedra, corners with fourteen equivalent Ho(1)Ho8Np4 cuboctahedra, edges with six equivalent Np(1)Ho12 cuboctahedra, edges with twelve equivalent Ho(1)Ho8Np4 cuboctahedra, faces with four equivalent Np(1)Ho12 cuboctahedra, and faces with sixteen equivalent Ho(1)Ho8Np4 cuboctahedra. There are a spread of Ho(1)-Ho(1) bond distances ranging from 3.46-3.55 Å.