Tm2Fe3Si5 crystallizes in the tetragonal P4/mnc space group. Tm(1) is bonded in a 13-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Si(2), three equivalent Si(3), and four equivalent Si(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to two equivalent Tm(1), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to four equivalent Tm(1), two equivalent Fe(2), two equivalent Si(1), and four equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Tm(1), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Si(1) atoms. In the second Si site, Si(1) is bonded in a 11-coordinate geometry to four equivalent Tm(1), one Fe(2), two equivalent Fe(1), two equivalent Si(1), and two equivalent Si(3) atoms. In the third Si site, Si(2) is bonded in a 8-coordinate geometry to four equivalent Tm(1) and four equivalent Fe(1) atoms.
Tm2Fe3Si5 crystallizes in the tetragonal P4/mnc space group. Tm(1) is bonded in a 13-coordinate geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Si(2), three equivalent Si(3), and four equivalent Si(1) atoms. Both Tm(1)-Fe(1) bond lengths are 3.03 Å. Both Tm(1)-Fe(2) bond lengths are 3.10 Å. Both Tm(1)-Si(2) bond lengths are 2.90 Å. There is one shorter (2.72 Å) and two longer (2.86 Å) Tm(1)-Si(3) bond lengths. There are two shorter (2.98 Å) and two longer (3.00 Å) Tm(1)-Si(1) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to two equivalent Tm(1), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. Both Fe(1)-Si(1) bond lengths are 2.33 Å. Both Fe(1)-Si(2) bond lengths are 2.32 Å. There is one shorter (2.33 Å) and one longer (2.37 Å) Fe(1)-Si(3) bond length. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to four equivalent Tm(1), two equivalent Fe(2), two equivalent Si(1), and four equivalent Si(3) atoms. Both Fe(2)-Fe(2) bond lengths are 2.69 Å. Both Fe(2)-Si(1) bond lengths are 2.57 Å. All Fe(2)-Si(3) bond lengths are 2.30 Å. There are three inequivalent Si sites. In the first Si site, Si(3) is bonded in a 9-coordinate geometry to three equivalent Tm(1), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Si(1) atoms. Both Si(3)-Si(1) bond lengths are 2.45 Å. In the second Si site, Si(1) is bonded in a 11-coordinate geometry to four equivalent Tm(1), one Fe(2), two equivalent Fe(1), two equivalent Si(1), and two equivalent Si(3) atoms. Both Si(1)-Si(1) bond lengths are 2.69 Å. In the third Si site, Si(2) is bonded in a 8-coordinate geometry to four equivalent Tm(1) and four equivalent Fe(1) atoms.