Np(IrSi)2 crystallizes in the tetragonal P4/nmm space group. Np(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Ir(2), four equivalent Si(1), and four equivalent Si(2) atoms. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to four equivalent Np(1) and four equivalent Si(2) atoms to form distorted IrNp4Si4 tetrahedra that share corners with twelve equivalent Si(1)Np4Ir4 tetrahedra, edges with two equivalent Si(1)Np4Ir4 tetrahedra, edges with four equivalent Ir(1)Np4Si4 tetrahedra, and faces with four equivalent Ir(1)Np4Si4 tetrahedra. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to four equivalent Np(1), one Si(2), and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to four equivalent Np(1) and four equivalent Ir(2) atoms to form distorted SiNp4Ir4 tetrahedra that share corners with twelve equivalent Ir(1)Np4Si4 tetrahedra, edges with two equivalent Ir(1)Np4Si4 tetrahedra, edges with four equivalent Si(1)Np4Ir4 tetrahedra, and faces with four equivalent Si(1)Np4Ir4 tetrahedra. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to four equivalent Np(1), one Ir(2), and four equivalent Ir(1) atoms.
Np(IrSi)2 crystallizes in the tetragonal P4/nmm space group. Np(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Ir(2), four equivalent Si(1), and four equivalent Si(2) atoms. All Np(1)-Ir(1) bond lengths are 3.26 Å. All Np(1)-Ir(2) bond lengths are 3.13 Å. All Np(1)-Si(1) bond lengths are 3.16 Å. All Np(1)-Si(2) bond lengths are 3.17 Å. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to four equivalent Np(1) and four equivalent Si(2) atoms to form distorted IrNp4Si4 tetrahedra that share corners with twelve equivalent Si(1)Np4Ir4 tetrahedra, edges with two equivalent Si(1)Np4Ir4 tetrahedra, edges with four equivalent Ir(1)Np4Si4 tetrahedra, and faces with four equivalent Ir(1)Np4Si4 tetrahedra. All Ir(1)-Si(2) bond lengths are 2.43 Å. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to four equivalent Np(1), one Si(2), and four equivalent Si(1) atoms. The Ir(2)-Si(2) bond length is 2.38 Å. All Ir(2)-Si(1) bond lengths are 2.42 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to four equivalent Np(1) and four equivalent Ir(2) atoms to form distorted SiNp4Ir4 tetrahedra that share corners with twelve equivalent Ir(1)Np4Si4 tetrahedra, edges with two equivalent Ir(1)Np4Si4 tetrahedra, edges with four equivalent Si(1)Np4Ir4 tetrahedra, and faces with four equivalent Si(1)Np4Ir4 tetrahedra. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to four equivalent Np(1), one Ir(2), and four equivalent Ir(1) atoms.