TmRhIn5 crystallizes in the tetragonal P4/mmm space group. Tm(1) is bonded to four equivalent In(2) and eight equivalent In(1) atoms to form TmIn12 cuboctahedra that share corners with four equivalent Tm(1)In12 cuboctahedra, faces with four equivalent Tm(1)In12 cuboctahedra, and faces with four equivalent In(2)Tm4In8 cuboctahedra. Rh(1) is bonded in a body-centered cubic geometry to eight equivalent In(1) atoms. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 4-coordinate geometry to two equivalent Tm(1), two equivalent Rh(1), and two equivalent In(2) atoms. In the second In site, In(2) is bonded to four equivalent Tm(1) and eight equivalent In(1) atoms to form InTm4In8 cuboctahedra that share corners with four equivalent In(2)Tm4In8 cuboctahedra, faces with four equivalent Tm(1)In12 cuboctahedra, and faces with four equivalent In(2)Tm4In8 cuboctahedra.
TmRhIn5 crystallizes in the tetragonal P4/mmm space group. Tm(1) is bonded to four equivalent In(2) and eight equivalent In(1) atoms to form TmIn12 cuboctahedra that share corners with four equivalent Tm(1)In12 cuboctahedra, faces with four equivalent Tm(1)In12 cuboctahedra, and faces with four equivalent In(2)Tm4In8 cuboctahedra. All Tm(1)-In(2) bond lengths are 3.27 Å. All Tm(1)-In(1) bond lengths are 3.20 Å. Rh(1) is bonded in a body-centered cubic geometry to eight equivalent In(1) atoms. All Rh(1)-In(1) bond lengths are 2.75 Å. There are two inequivalent In sites. In the first In site, In(1) is bonded in a 4-coordinate geometry to two equivalent Tm(1), two equivalent Rh(1), and two equivalent In(2) atoms. Both In(1)-In(2) bond lengths are 3.20 Å. In the second In site, In(2) is bonded to four equivalent Tm(1) and eight equivalent In(1) atoms to form InTm4In8 cuboctahedra that share corners with four equivalent In(2)Tm4In8 cuboctahedra, faces with four equivalent Tm(1)In12 cuboctahedra, and faces with four equivalent In(2)Tm4In8 cuboctahedra.