SmMn6Ge6 crystallizes in the hexagonal P6/mmm space group. Sm(1) is bonded to two equivalent Ge(3) and six equivalent Ge(1) atoms to form distorted edge-sharing SmGe8 hexagonal bipyramids. Mn(1) is bonded in a 6-coordinate geometry to two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Sm(1) and six equivalent Mn(1) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to six equivalent Mn(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to one Sm(1), six equivalent Mn(1), and one Ge(3) atom.
SmMn6Ge6 crystallizes in the hexagonal P6/mmm space group. Sm(1) is bonded to two equivalent Ge(3) and six equivalent Ge(1) atoms to form distorted edge-sharing SmGe8 hexagonal bipyramids. Both Sm(1)-Ge(3) bond lengths are 2.83 Å. All Sm(1)-Ge(1) bond lengths are 3.01 Å. Mn(1) is bonded in a 6-coordinate geometry to two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. Both Mn(1)-Ge(1) bond lengths are 2.54 Å. Both Mn(1)-Ge(2) bond lengths are 2.52 Å. Both Mn(1)-Ge(3) bond lengths are 2.72 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Sm(1) and six equivalent Mn(1) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to six equivalent Mn(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to one Sm(1), six equivalent Mn(1), and one Ge(3) atom. The Ge(3)-Ge(3) bond length is 2.50 Å.