NpEr3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Np(1) is bonded to twelve equivalent Er(1) atoms to form NpEr12 cuboctahedra that share corners with twelve equivalent Np(1)Er12 cuboctahedra, edges with twenty-four equivalent Er(1)Er8Np4 cuboctahedra, faces with six equivalent Np(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Er8Np4 cuboctahedra. Er(1) is bonded to four equivalent Np(1) and eight equivalent Er(1) atoms to form ErEr8Np4 cuboctahedra that share corners with twelve equivalent Er(1)Er8Np4 cuboctahedra, edges with eight equivalent Np(1)Er12 cuboctahedra, edges with sixteen equivalent Er(1)Er8Np4 cuboctahedra, faces with four equivalent Np(1)Er12 cuboctahedra, and faces with fourteen equivalent Er(1)Er8Np4 cuboctahedra.
NpEr3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. Np(1) is bonded to twelve equivalent Er(1) atoms to form NpEr12 cuboctahedra that share corners with twelve equivalent Np(1)Er12 cuboctahedra, edges with twenty-four equivalent Er(1)Er8Np4 cuboctahedra, faces with six equivalent Np(1)Er12 cuboctahedra, and faces with twelve equivalent Er(1)Er8Np4 cuboctahedra. All Np(1)-Er(1) bond lengths are 3.50 Å. Er(1) is bonded to four equivalent Np(1) and eight equivalent Er(1) atoms to form ErEr8Np4 cuboctahedra that share corners with twelve equivalent Er(1)Er8Np4 cuboctahedra, edges with eight equivalent Np(1)Er12 cuboctahedra, edges with sixteen equivalent Er(1)Er8Np4 cuboctahedra, faces with four equivalent Np(1)Er12 cuboctahedra, and faces with fourteen equivalent Er(1)Er8Np4 cuboctahedra. All Er(1)-Er(1) bond lengths are 3.50 Å.