ErZr crystallizes in the hexagonal P-6m2 space group. Er(1) is bonded to six equivalent Er(1) and six equivalent Zr(1) atoms to form ErEr6Zr6 cuboctahedra that share corners with eighteen equivalent Er(1)Er6Zr6 cuboctahedra, edges with six equivalent Er(1)Er6Zr6 cuboctahedra, edges with twelve equivalent Zr(1)Er6Zr6 cuboctahedra, faces with eight equivalent Er(1)Er6Zr6 cuboctahedra, and faces with twelve equivalent Zr(1)Er6Zr6 cuboctahedra. Zr(1) is bonded to six equivalent Er(1) and six equivalent Zr(1) atoms to form ZrEr6Zr6 cuboctahedra that share corners with eighteen equivalent Zr(1)Er6Zr6 cuboctahedra, edges with six equivalent Zr(1)Er6Zr6 cuboctahedra, edges with twelve equivalent Er(1)Er6Zr6 cuboctahedra, faces with eight equivalent Zr(1)Er6Zr6 cuboctahedra, and faces with twelve equivalent Er(1)Er6Zr6 cuboctahedra.
ErZr crystallizes in the hexagonal P-6m2 space group. Er(1) is bonded to six equivalent Er(1) and six equivalent Zr(1) atoms to form ErEr6Zr6 cuboctahedra that share corners with eighteen equivalent Er(1)Er6Zr6 cuboctahedra, edges with six equivalent Er(1)Er6Zr6 cuboctahedra, edges with twelve equivalent Zr(1)Er6Zr6 cuboctahedra, faces with eight equivalent Er(1)Er6Zr6 cuboctahedra, and faces with twelve equivalent Zr(1)Er6Zr6 cuboctahedra. All Er(1)-Er(1) bond lengths are 3.40 Å. All Er(1)-Zr(1) bond lengths are 3.31 Å. Zr(1) is bonded to six equivalent Er(1) and six equivalent Zr(1) atoms to form ZrEr6Zr6 cuboctahedra that share corners with eighteen equivalent Zr(1)Er6Zr6 cuboctahedra, edges with six equivalent Zr(1)Er6Zr6 cuboctahedra, edges with twelve equivalent Er(1)Er6Zr6 cuboctahedra, faces with eight equivalent Zr(1)Er6Zr6 cuboctahedra, and faces with twelve equivalent Er(1)Er6Zr6 cuboctahedra. All Zr(1)-Zr(1) bond lengths are 3.40 Å.