TmFeGe2 crystallizes in the orthorhombic Cmcm space group. Tm(1) is bonded in a 14-coordinate geometry to four equivalent Fe(1), four equivalent Ge(2), and six equivalent Ge(1) atoms. Fe(1) is bonded in a 5-coordinate geometry to four equivalent Tm(1), one Ge(1), and four equivalent Ge(2) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to six equivalent Tm(1), one Fe(1), and two equivalent Ge(1) atoms. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to four equivalent Tm(1) and four equivalent Fe(1) atoms.
TmFeGe2 crystallizes in the orthorhombic Cmcm space group. Tm(1) is bonded in a 14-coordinate geometry to four equivalent Fe(1), four equivalent Ge(2), and six equivalent Ge(1) atoms. All Tm(1)-Fe(1) bond lengths are 3.13 Å. There are two shorter (3.08 Å) and two longer (3.17 Å) Tm(1)-Ge(2) bond lengths. There are four shorter (3.11 Å) and two longer (3.28 Å) Tm(1)-Ge(1) bond lengths. Fe(1) is bonded in a 5-coordinate geometry to four equivalent Tm(1), one Ge(1), and four equivalent Ge(2) atoms. The Fe(1)-Ge(1) bond length is 2.25 Å. All Fe(1)-Ge(2) bond lengths are 2.38 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 9-coordinate geometry to six equivalent Tm(1), one Fe(1), and two equivalent Ge(1) atoms. Both Ge(1)-Ge(1) bond lengths are 2.56 Å. In the second Ge site, Ge(2) is bonded in a 4-coordinate geometry to four equivalent Tm(1) and four equivalent Fe(1) atoms.