NaEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent Eu(2) and eight equivalent Eu(1) atoms to form NaEu12 cuboctahedra that share corners with four equivalent Na(1)Eu12 cuboctahedra, corners with eight equivalent Eu(2)Na4Eu8 cuboctahedra, edges with eight equivalent Na(1)Eu12 cuboctahedra, edges with sixteen equivalent Eu(1)Na4Eu8 cuboctahedra, faces with four equivalent Na(1)Eu12 cuboctahedra, faces with six equivalent Eu(2)Na4Eu8 cuboctahedra, and faces with eight equivalent Eu(1)Na4Eu8 cuboctahedra. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to four equivalent Na(1), four equivalent Eu(1), and four equivalent Eu(2) atoms to form EuNa4Eu8 cuboctahedra that share corners with twelve equivalent Eu(1)Na4Eu8 cuboctahedra, edges with eight equivalent Na(1)Eu12 cuboctahedra, edges with eight equivalent Eu(1)Na4Eu8 cuboctahedra, edges with eight equivalent Eu(2)Na4Eu8 cuboctahedra, faces with four equivalent Na(1)Eu12 cuboctahedra, faces with four equivalent Eu(2)Na4Eu8 cuboctahedra, and faces with ten equivalent Eu(1)Na4Eu8 cuboctahedra. In the second Eu site, Eu(2) is bonded to four equivalent Na(1) and eight equivalent Eu(1) atoms to form distorted EuNa4Eu8 cuboctahedra that share corners with four equivalent Eu(2)Na4Eu8 cuboctahedra, corners with eight equivalent Na(1)Eu12 cuboctahedra, edges with eight equivalent Eu(2)Na4Eu8 cuboctahedra, edges with sixteen equivalent Eu(1)Na4Eu8 cuboctahedra, faces with four equivalent Eu(2)Na4Eu8 cuboctahedra, faces with six equivalent Na(1)Eu12 cuboctahedra, and faces with eight equivalent Eu(1)Na4Eu8 cuboctahedra.
NaEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent Eu(2) and eight equivalent Eu(1) atoms to form NaEu12 cuboctahedra that share corners with four equivalent Na(1)Eu12 cuboctahedra, corners with eight equivalent Eu(2)Na4Eu8 cuboctahedra, edges with eight equivalent Na(1)Eu12 cuboctahedra, edges with sixteen equivalent Eu(1)Na4Eu8 cuboctahedra, faces with four equivalent Na(1)Eu12 cuboctahedra, faces with six equivalent Eu(2)Na4Eu8 cuboctahedra, and faces with eight equivalent Eu(1)Na4Eu8 cuboctahedra. All Na(1)-Eu(2) bond lengths are 3.87 Å. All Na(1)-Eu(1) bond lengths are 4.04 Å. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to four equivalent Na(1), four equivalent Eu(1), and four equivalent Eu(2) atoms to form EuNa4Eu8 cuboctahedra that share corners with twelve equivalent Eu(1)Na4Eu8 cuboctahedra, edges with eight equivalent Na(1)Eu12 cuboctahedra, edges with eight equivalent Eu(1)Na4Eu8 cuboctahedra, edges with eight equivalent Eu(2)Na4Eu8 cuboctahedra, faces with four equivalent Na(1)Eu12 cuboctahedra, faces with four equivalent Eu(2)Na4Eu8 cuboctahedra, and faces with ten equivalent Eu(1)Na4Eu8 cuboctahedra. All Eu(1)-Eu(1) bond lengths are 3.87 Å. All Eu(1)-Eu(2) bond lengths are 4.04 Å. In the second Eu site, Eu(2) is bonded to four equivalent Na(1) and eight equivalent Eu(1) atoms to form distorted EuNa4Eu8 cuboctahedra that share corners with four equivalent Eu(2)Na4Eu8 cuboctahedra, corners with eight equivalent Na(1)Eu12 cuboctahedra, edges with eight equivalent Eu(2)Na4Eu8 cuboctahedra, edges with sixteen equivalent Eu(1)Na4Eu8 cuboctahedra, faces with four equivalent Eu(2)Na4Eu8 cuboctahedra, faces with six equivalent Na(1)Eu12 cuboctahedra, and faces with eight equivalent Eu(1)Na4Eu8 cuboctahedra.