Er3Pm is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Er(1) is bonded to eight equivalent Er(1) and four equivalent Pm(1) atoms to form ErPm4Er8 cuboctahedra that share corners with twelve equivalent Er(1)Pm4Er8 cuboctahedra, edges with eight equivalent Pm(1)Er12 cuboctahedra, edges with sixteen equivalent Er(1)Pm4Er8 cuboctahedra, faces with four equivalent Pm(1)Er12 cuboctahedra, and faces with fourteen equivalent Er(1)Pm4Er8 cuboctahedra. Pm(1) is bonded to twelve equivalent Er(1) atoms to form PmEr12 cuboctahedra that share corners with twelve equivalent Pm(1)Er12 cuboctahedra, edges with twenty-four equivalent Er(1)Pm4Er8 cuboctahedra, faces with six equivalent Pm(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Pm4Er8 cuboctahedra.
Er3Pm is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Er(1) is bonded to eight equivalent Er(1) and four equivalent Pm(1) atoms to form ErPm4Er8 cuboctahedra that share corners with twelve equivalent Er(1)Pm4Er8 cuboctahedra, edges with eight equivalent Pm(1)Er12 cuboctahedra, edges with sixteen equivalent Er(1)Pm4Er8 cuboctahedra, faces with four equivalent Pm(1)Er12 cuboctahedra, and faces with fourteen equivalent Er(1)Pm4Er8 cuboctahedra. All Er(1)-Er(1) bond lengths are 3.54 Å. All Er(1)-Pm(1) bond lengths are 3.54 Å. Pm(1) is bonded to twelve equivalent Er(1) atoms to form PmEr12 cuboctahedra that share corners with twelve equivalent Pm(1)Er12 cuboctahedra, edges with twenty-four equivalent Er(1)Pm4Er8 cuboctahedra, faces with six equivalent Pm(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Pm4Er8 cuboctahedra.