Materials Data on K3Pm by Materials Project
K3Pm is beta Cu3Ti-like structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight equivalent K and four equivalent Pm atoms to form distorted KK8Pm4 cuboctahedra that share corners with four equivalent PmK12 cuboctahedra, corners with fourteen KK8Pm4 cuboctahedra, edges with six equivalent PmK12 cuboctahedra, edges with twelve equivalent KK8Pm4 cuboctahedra, faces with four equivalent PmK12 cuboctahedra, and faces with sixteen KK8Pm4 cuboctahedra. There are a spread of K–K bond distances ranging from 4.23–4.44 Å. There are two shorter (4.31 Å) and two longer (4.33 Å) K–Pm bond lengths. In the second K site, K is bonded to eight K and four equivalent Pm atoms to form distorted KK8Pm4 cuboctahedra that share corners with four equivalent PmK12 cuboctahedra, corners with fourteen KK8Pm4 cuboctahedra, edges with six equivalent PmK12 cuboctahedra, edges with twelve KK8Pm4 cuboctahedra, faces with four equivalent PmK12 cuboctahedra, and faces with sixteen KK8Pm4 cuboctahedra. There are a spread of K–K bond distances ranging from 4.22–4.43 Å. There are two shorter (4.31 Å) and two longer (4.33 Å) K–Pm bond lengths. Pm is bonded to twelve K atoms to form PmK12 cuboctahedra that share corners with six equivalent PmK12 cuboctahedra, corners with twelve KK8Pm4 cuboctahedra, edges with eighteen KK8Pm4 cuboctahedra, faces with eight equivalent PmK12 cuboctahedra, and faces with twelve KK8Pm4 cuboctahedra.