Tm12Fe2Pb3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(2), and two equivalent Pb(1) atoms. In the second Tm site, Tm(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent Pb(1) atoms. Fe(1) is bonded in a 9-coordinate geometry to four equivalent Tm(1), four equivalent Tm(2), and one Fe(1) atom. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to four equivalent Tm(2) and eight equivalent Tm(1) atoms to form a mixture of distorted face and corner-sharing PbTm12 cuboctahedra. In the second Pb site, Pb(2) is bonded in a body-centered cubic geometry to eight equivalent Tm(1) atoms.
Tm12Fe2Pb3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(2), and two equivalent Pb(1) atoms. The Tm(1)-Fe(1) bond length is 2.91 Å. The Tm(1)-Pb(2) bond length is 3.13 Å. There is one shorter (3.19 Å) and one longer (3.77 Å) Tm(1)-Pb(1) bond length. In the second Tm site, Tm(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1) and two equivalent Pb(1) atoms. Both Tm(2)-Fe(1) bond lengths are 2.85 Å. Both Tm(2)-Pb(1) bond lengths are 3.51 Å. Fe(1) is bonded in a 9-coordinate geometry to four equivalent Tm(1), four equivalent Tm(2), and one Fe(1) atom. The Fe(1)-Fe(1) bond length is 2.35 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to four equivalent Tm(2) and eight equivalent Tm(1) atoms to form a mixture of distorted face and corner-sharing PbTm12 cuboctahedra. In the second Pb site, Pb(2) is bonded in a body-centered cubic geometry to eight equivalent Tm(1) atoms.