TbIr2Si2 crystallizes in the tetragonal I4/mmm space group. Tb(1) is bonded in a 16-coordinate geometry to eight equivalent Ir(1) and eight equivalent Si(1) atoms. Ir(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form a mixture of distorted corner, face, and edge-sharing IrTb4Si4 tetrahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent Tb(1), four equivalent Ir(1), and one Si(1) atom.
TbIr2Si2 crystallizes in the tetragonal I4/mmm space group. Tb(1) is bonded in a 16-coordinate geometry to eight equivalent Ir(1) and eight equivalent Si(1) atoms. All Tb(1)-Ir(1) bond lengths are 3.21 Å. All Tb(1)-Si(1) bond lengths are 3.12 Å. Ir(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form a mixture of distorted corner, face, and edge-sharing IrTb4Si4 tetrahedra. All Ir(1)-Si(1) bond lengths are 2.40 Å. Si(1) is bonded in a 9-coordinate geometry to four equivalent Tb(1), four equivalent Ir(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.42 Å.