TmMn6Ge5Ga1 crystallizes in the hexagonal P6mm space group. Tm(1) is bonded to one Ga(1), one Ge(3), and six equivalent Ge(1) atoms to form distorted TmGaGe7 hexagonal bipyramids that share  a cornercorner with one Ge(3)TmMn6Ga hexagonal bipyramid and edges with six equivalent Tm(1)GaGe7 hexagonal bipyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to two equivalent Ga(1), two equivalent Ge(1), and two equivalent Ge(2) atoms. Ga(1) is bonded in a 8-coordinate geometry to one Tm(1), six equivalent Mn(2), and one Ge(3) atom. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Tm(1), three equivalent Mn(1), and three equivalent Mn(2) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to three equivalent Mn(1) and three equivalent Mn(2) atoms. In the third Ge site, Ge(3) is bonded to one Tm(1), six equivalent Mn(1), and one Ga(1) atom to form distorted GeTmMn6Ga hexagonal bipyramids that share  a cornercorner with one Tm(1)GaGe7 hexagonal bipyramid and corners with six equivalent Ge(3)TmMn6Ga hexagonal bipyramids.
TmMn6Ge5Ga1 crystallizes in the hexagonal P6mm space group. Tm(1) is bonded to one Ga(1), one Ge(3), and six equivalent Ge(1) atoms to form distorted TmGaGe7 hexagonal bipyramids that share  a cornercorner with one Ge(3)TmMn6Ga hexagonal bipyramid and edges with six equivalent Tm(1)GaGe7 hexagonal bipyramids. The Tm(1)-Ga(1) bond length is 2.81 Å. The Tm(1)-Ge(3) bond length is 2.80 Å. All Tm(1)-Ge(1) bond lengths are 3.00 Å. There are two inequivalent Mn sites. In the first Mn site, 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 2.52 Å. Both Mn(1)-Ge(2) bond lengths are 2.54 Å. Both Mn(1)-Ge(3) bond lengths are 2.70 Å. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to two equivalent Ga(1), two equivalent Ge(1), and two equivalent Ge(2) atoms. Both Mn(2)-Ga(1) bond lengths are 2.72 Å. Both Mn(2)-Ge(1) bond lengths are 2.51 Å. Both Mn(2)-Ge(2) bond lengths are 2.52 Å. Ga(1) is bonded in a 8-coordinate geometry to one Tm(1), six equivalent Mn(2), and one Ge(3) atom. The Ga(1)-Ge(3) bond length is 2.51 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to three equivalent Tm(1), three equivalent Mn(1), and three equivalent Mn(2) atoms. In the second Ge site, Ge(2) is bonded in a 6-coordinate geometry to three equivalent Mn(1) and three equivalent Mn(2) atoms. In the third Ge site, Ge(3) is bonded to one Tm(1), six equivalent Mn(1), and one Ga(1) atom to form distorted GeTmMn6Ga hexagonal bipyramids that share  a cornercorner with one Tm(1)GaGe7 hexagonal bipyramid and corners with six equivalent Ge(3)TmMn6Ga hexagonal bipyramids.