Tm5Ir3 crystallizes in the tetragonal P4/ncc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent Ir(2) and three equivalent Ir(1) atoms to form distorted TmIr5 trigonal bipyramids that share corners with four equivalent Tm(2)Ir4 tetrahedra, corners with eleven equivalent Tm(1)Ir5 trigonal bipyramids,  an edgeedge with one Tm(2)Ir4 tetrahedra, edges with six equivalent Tm(1)Ir5 trigonal bipyramids, and faces with two equivalent Tm(1)Ir5 trigonal bipyramids. In the second Tm site, Tm(2) is bonded to four equivalent Ir(1) atoms to form TmIr4 tetrahedra that share corners with sixteen equivalent Tm(1)Ir5 trigonal bipyramids, edges with two equivalent Tm(2)Ir4 tetrahedra, and edges with four equivalent Tm(1)Ir5 trigonal bipyramids. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a 8-coordinate geometry to two equivalent Tm(2) and six equivalent Tm(1) atoms. In the second Ir site, Ir(2) is bonded in a 8-coordinate geometry to eight equivalent Tm(1) atoms.
Tm5Ir3 crystallizes in the tetragonal P4/ncc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent Ir(2) and three equivalent Ir(1) atoms to form distorted TmIr5 trigonal bipyramids that share corners with four equivalent Tm(2)Ir4 tetrahedra, corners with eleven equivalent Tm(1)Ir5 trigonal bipyramids,  an edgeedge with one Tm(2)Ir4 tetrahedra, edges with six equivalent Tm(1)Ir5 trigonal bipyramids, and faces with two equivalent Tm(1)Ir5 trigonal bipyramids. There is one shorter (2.86 Å) and one longer (2.89 Å) Tm(1)-Ir(2) bond length. There are a spread of Tm(1)-Ir(1) bond distances ranging from 2.83-3.07 Å. In the second Tm site, Tm(2) is bonded to four equivalent Ir(1) atoms to form TmIr4 tetrahedra that share corners with sixteen equivalent Tm(1)Ir5 trigonal bipyramids, edges with two equivalent Tm(2)Ir4 tetrahedra, and edges with four equivalent Tm(1)Ir5 trigonal bipyramids. All Tm(2)-Ir(1) bond lengths are 2.80 Å. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a 8-coordinate geometry to two equivalent Tm(2) and six equivalent Tm(1) atoms. In the second Ir site, Ir(2) is bonded in a 8-coordinate geometry to eight equivalent Tm(1) atoms.