TbIrRhSi2 crystallizes in the tetragonal I-4m2 space group. Tb(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Rh(1), and eight equivalent Si(1) atoms. Ir(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form distorted IrTb4Si4 tetrahedra that share corners with four equivalent Rh(1)Tb4Si4 tetrahedra, corners with eight equivalent Ir(1)Tb4Si4 tetrahedra, edges with two equivalent Rh(1)Tb4Si4 tetrahedra, edges with four equivalent Ir(1)Tb4Si4 tetrahedra, and faces with four equivalent Rh(1)Tb4Si4 tetrahedra. Rh(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form distorted RhTb4Si4 tetrahedra that share corners with four equivalent Ir(1)Tb4Si4 tetrahedra, corners with eight equivalent Rh(1)Tb4Si4 tetrahedra, edges with two equivalent Ir(1)Tb4Si4 tetrahedra, edges with four equivalent Rh(1)Tb4Si4 tetrahedra, and faces with four equivalent Ir(1)Tb4Si4 tetrahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent Tb(1), two equivalent Ir(1), two equivalent Rh(1), and one Si(1) atom.
TbIrRhSi2 crystallizes in the tetragonal I-4m2 space group. Tb(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Rh(1), and eight equivalent Si(1) atoms. All Tb(1)-Ir(1) bond lengths are 3.23 Å. All Tb(1)-Rh(1) bond lengths are 3.23 Å. All Tb(1)-Si(1) bond lengths are 3.13 Å. Ir(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form distorted IrTb4Si4 tetrahedra that share corners with four equivalent Rh(1)Tb4Si4 tetrahedra, corners with eight equivalent Ir(1)Tb4Si4 tetrahedra, edges with two equivalent Rh(1)Tb4Si4 tetrahedra, edges with four equivalent Ir(1)Tb4Si4 tetrahedra, and faces with four equivalent Rh(1)Tb4Si4 tetrahedra. All Ir(1)-Si(1) bond lengths are 2.41 Å. Rh(1) is bonded to four equivalent Tb(1) and four equivalent Si(1) atoms to form distorted RhTb4Si4 tetrahedra that share corners with four equivalent Ir(1)Tb4Si4 tetrahedra, corners with eight equivalent Rh(1)Tb4Si4 tetrahedra, edges with two equivalent Ir(1)Tb4Si4 tetrahedra, edges with four equivalent Rh(1)Tb4Si4 tetrahedra, and faces with four equivalent Ir(1)Tb4Si4 tetrahedra. All Rh(1)-Si(1) bond lengths are 2.41 Å. Si(1) is bonded in a 9-coordinate geometry to four equivalent Tb(1), two equivalent Ir(1), two equivalent Rh(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.43 Å.