Th2(IrSi)3 crystallizes in the tetragonal P4/mmm space group. Th(1) is bonded in a 6-coordinate geometry to four equivalent Th(1), one Ir(1), and one Si(1) atom. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a linear geometry to one Th(1) and one Si(2) atom. In the second Ir site, Ir(2) is bonded in a linear geometry to two equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted linear geometry to one Th(1) and one Ir(2) atom. In the second Si site, Si(2) is bonded in a linear geometry to two equivalent Ir(1) atoms.
Th2(IrSi)3 crystallizes in the tetragonal P4/mmm space group. Th(1) is bonded in a 6-coordinate geometry to four equivalent Th(1), one Ir(1), and one Si(1) atom. All Th(1)-Th(1) bond lengths are 2.90 Å. The Th(1)-Ir(1) bond length is 2.59 Å. The Th(1)-Si(1) bond length is 3.01 Å. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a linear geometry to one Th(1) and one Si(2) atom. The Ir(1)-Si(2) bond length is 2.32 Å. In the second Ir site, Ir(2) is bonded in a linear geometry to two equivalent Si(1) atoms. Both Ir(2)-Si(1) bond lengths are 2.28 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted linear geometry to one Th(1) and one Ir(2) atom. In the second Si site, Si(2) is bonded in a linear geometry to two equivalent Ir(1) atoms.