Materials Data on K3Er by Materials Project
K3Er is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. K is bonded to eight equivalent K and four equivalent Er atoms to form distorted KK8Er4 cuboctahedra that share corners with four equivalent ErK12 cuboctahedra, corners with fourteen equivalent KK8Er4 cuboctahedra, edges with six equivalent ErK12 cuboctahedra, edges with twelve equivalent KK8Er4 cuboctahedra, faces with four equivalent ErK12 cuboctahedra, and faces with sixteen equivalent KK8Er4 cuboctahedra. There are a spread of K–K bond distances ranging from 4.15–4.44 Å. There are two shorter (4.27 Å) and two longer (4.30 Å) K–Er bond lengths. Er is bonded to twelve equivalent K atoms to form ErK12 cuboctahedra that share corners with six equivalent ErK12 cuboctahedra, corners with twelve equivalent KK8Er4 cuboctahedra, edges with eighteen equivalent KK8Er4 cuboctahedra, faces with eight equivalent ErK12 cuboctahedra, and faces with twelve equivalent KK8Er4 cuboctahedra.