Er3Ir4Si13 crystallizes in the cubic Pm-3n space group. Er(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1) and twelve equivalent Si(2) atoms. Ir(1) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 2-coordinate geometry to three equivalent Er(1), two equivalent Ir(1), and one Si(1) atom. In the second Si site, Si(1) is bonded in a cuboctahedral geometry to twelve equivalent Si(2) atoms.
Er3Ir4Si13 crystallizes in the cubic Pm-3n space group. Er(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1) and twelve equivalent Si(2) atoms. All Er(1)-Ir(1) bond lengths are 3.09 Å. There are eight shorter (3.08 Å) and four longer (3.19 Å) Er(1)-Si(2) bond lengths. Ir(1) is bonded in a 9-coordinate geometry to three equivalent Er(1) and six equivalent Si(2) atoms. All Ir(1)-Si(2) bond lengths are 2.43 Å. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 2-coordinate geometry to three equivalent Er(1), two equivalent Ir(1), and one Si(1) atom. The Si(2)-Si(1) bond length is 2.84 Å. In the second Si site, Si(1) is bonded in a cuboctahedral geometry to twelve equivalent Si(2) atoms.