Na10EuSn12 crystallizes in the cubic I-43m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 9-coordinate geometry to one Eu(1) and nine equivalent Sn(1) atoms. In the second Na site, Na(2) is bonded to four equivalent Sn(1) atoms to form corner-sharing NaSn4 tetrahedra. Eu(1) is bonded in a 16-coordinate geometry to four equivalent Na(1) and twelve equivalent Sn(1) atoms. Sn(1) is bonded in a 9-coordinate geometry to two equivalent Na(2), three equivalent Na(1), one Eu(1), and three equivalent Sn(1) atoms.
Na10EuSn12 crystallizes in the cubic I-43m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 9-coordinate geometry to one Eu(1) and nine equivalent Sn(1) atoms. The Na(1)-Eu(1) bond length is 3.79 Å. There are three shorter (3.41 Å) and six longer (3.54 Å) Na(1)-Sn(1) bond lengths. In the second Na site, Na(2) is bonded to four equivalent Sn(1) atoms to form corner-sharing NaSn4 tetrahedra. All Na(2)-Sn(1) bond lengths are 3.22 Å. Eu(1) is bonded in a 16-coordinate geometry to four equivalent Na(1) and twelve equivalent Sn(1) atoms. All Eu(1)-Sn(1) bond lengths are 3.45 Å. Sn(1) is bonded in a 9-coordinate geometry to two equivalent Na(2), three equivalent Na(1), one Eu(1), and three equivalent Sn(1) atoms. There is one shorter (2.90 Å) and two longer (2.98 Å) Sn(1)-Sn(1) bond lengths.