TmGe3 crystallizes in the orthorhombic Cmcm space group. Tm(1) is bonded in a 10-coordinate geometry to two equivalent Ge(2), two equivalent Ge(3), and six equivalent Ge(1) atoms. There are three inequivalent Ge sites. In the first Ge site, Ge(3) is bonded in a 7-coordinate geometry to two equivalent Tm(1) and five equivalent Ge(2) atoms. In the second Ge site, Ge(1) is bonded in a 8-coordinate geometry to six equivalent Tm(1) and two equivalent Ge(1) atoms. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to two equivalent Tm(1) and five equivalent Ge(3) atoms.
TmGe3 crystallizes in the orthorhombic Cmcm space group. Tm(1) is bonded in a 10-coordinate geometry to two equivalent Ge(2), two equivalent Ge(3), and six equivalent Ge(1) atoms. Both Tm(1)-Ge(2) bond lengths are 2.96 Å. Both Tm(1)-Ge(3) bond lengths are 2.96 Å. There are four shorter (2.92 Å) and two longer (3.22 Å) Tm(1)-Ge(1) bond lengths. There are three inequivalent Ge sites. In the first Ge site, Ge(3) is bonded in a 7-coordinate geometry to two equivalent Tm(1) and five equivalent Ge(2) atoms. There is one shorter (2.47 Å) and four longer (2.77 Å) Ge(3)-Ge(2) bond lengths. In the second Ge site, Ge(1) is bonded in a 8-coordinate geometry to six equivalent Tm(1) and two equivalent Ge(1) atoms. Both Ge(1)-Ge(1) bond lengths are 2.52 Å. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to two equivalent Tm(1) and five equivalent Ge(3) atoms.