DOE OSTI2020
Na3Dy is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded to eight Na and four equivalent Dy atoms to form distorted NaNa8Dy4 cuboctahedra that share corners with four equivalent DyNa12 cuboctahedra, corners with fourteen NaNa8Dy4 cuboctahedra, edges with six equivalent DyNa12 cuboctahedra, edges with twelve NaNa8Dy4 cuboctahedra, faces with four equivalent DyNa12 cuboctahedra, and faces with sixteen NaNa8Dy4 cuboctahedra. There are a spread of Na–Na bond distances ranging from 3.56–3.72 Å. There are two shorter (3.63 Å) and two longer (3.64 Å) Na–Dy bond lengths. In the second Na site, Na is bonded to eight equivalent Na and four equivalent Dy atoms to form distorted NaNa8Dy4 cuboctahedra that share corners with four equivalent DyNa12 cuboctahedra, corners with fourteen NaNa8Dy4 cuboctahedra, edges with six equivalent DyNa12 cuboctahedra, edges with twelve equivalent NaNa8Dy4 cuboctahedra, faces with four equivalent DyNa12 cuboctahedra, and faces with sixteen NaNa8Dy4 cuboctahedra. There are two shorter (3.63 Å) and two longer (3.64 Å) Na–Dy bond lengths. Dy is bonded to twelve Na atoms to form DyNa12 cuboctahedra that share corners with six equivalent DyNa12 cuboctahedra, corners with twelve equivalent NaNa8Dy4 cuboctahedra, edges with eighteen NaNa8Dy4 cuboctahedra, faces with eight equivalent DyNa12 cuboctahedra, and faces with twelve NaNa8Dy4 cuboctahedra.