Mg4IrN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form a mixture of edge and corner-sharing MgN4 tetrahedra. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent N(2) and two equivalent N(3) atoms. In the third Mg site, Mg(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form MgN5 square pyramids that share corners with three equivalent Mg(4)N5 square pyramids,  a cornercorner with one Mg(1)N4 tetrahedra, edges with two equivalent Mg(3)N5 square pyramids, edges with three equivalent Mg(4)N5 square pyramids, and edges with two equivalent Mg(1)N4 tetrahedra. In the fourth Mg site, Mg(4) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form MgN5 square pyramids that share corners with three equivalent Mg(3)N5 square pyramids, corners with three equivalent Mg(1)N4 tetrahedra, edges with two equivalent Mg(4)N5 square pyramids, edges with three equivalent Mg(3)N5 square pyramids, and  an edgeedge with one Mg(1)N4 tetrahedra. Ir(1) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), one N(3), and one N(4) atom. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(3)Mg5Ir octahedra, corners with two equivalent N(4)Mg5Ir octahedra, corners with two equivalent N(2)Mg3Ir tetrahedra, edges with two equivalent N(1)Mg5Ir octahedra, edges with two equivalent N(3)Mg5Ir octahedra, and edges with four equivalent N(4)Mg5Ir octahedra. The corner-sharing octahedral tilt angles range from 8-12°. In the second N site, N(2) is bonded to one Mg(1), two equivalent Mg(2), and one Ir(1) atom to form NMg3Ir tetrahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with two equivalent N(4)Mg5Ir octahedra, corners with six equivalent N(3)Mg5Ir octahedra, and  an edgeedge with one N(2)Mg3Ir tetrahedra. The corner-sharing octahedral tilt angles range from 51-69°. In the third N site, N(3) is bonded to one Mg(1), one Mg(3), one Mg(4), two equivalent Mg(2), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with six equivalent N(2)Mg3Ir tetrahedra,  an edgeedge with one N(3)Mg5Ir octahedra, edges with two equivalent N(1)Mg5Ir octahedra, and edges with three equivalent N(4)Mg5Ir octahedra. The corner-sharing octahedral tilt angles are 8°. In the fourth N site, N(4) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with two equivalent N(2)Mg3Ir tetrahedra, edges with two equivalent N(4)Mg5Ir octahedra, edges with three equivalent N(3)Mg5Ir octahedra, and edges with four equivalent N(1)Mg5Ir octahedra. The corner-sharing octahedral tilt angles are 12°.
Mg4IrN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form a mixture of edge and corner-sharing MgN4 tetrahedra. The Mg(1)-N(1) bond length is 2.09 Å. The Mg(1)-N(2) bond length is 2.05 Å. The Mg(1)-N(3) bond length is 2.09 Å. The Mg(1)-N(4) bond length is 2.07 Å. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent N(2) and two equivalent N(3) atoms. There is one shorter (2.12 Å) and one longer (2.13 Å) Mg(2)-N(2) bond length. Both Mg(2)-N(3) bond lengths are 2.17 Å. In the third Mg site, Mg(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form MgN5 square pyramids that share corners with three equivalent Mg(4)N5 square pyramids,  a cornercorner with one Mg(1)N4 tetrahedra, edges with two equivalent Mg(3)N5 square pyramids, edges with three equivalent Mg(4)N5 square pyramids, and edges with two equivalent Mg(1)N4 tetrahedra. The Mg(3)-N(3) bond length is 2.21 Å. There is one shorter (2.11 Å) and one longer (2.23 Å) Mg(3)-N(1) bond length. There is one shorter (2.17 Å) and one longer (2.27 Å) Mg(3)-N(4) bond length. In the fourth Mg site, Mg(4) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form MgN5 square pyramids that share corners with three equivalent Mg(3)N5 square pyramids, corners with three equivalent Mg(1)N4 tetrahedra, edges with two equivalent Mg(4)N5 square pyramids, edges with three equivalent Mg(3)N5 square pyramids, and  an edgeedge with one Mg(1)N4 tetrahedra. The Mg(4)-N(3) bond length is 2.24 Å. There is one shorter (2.16 Å) and one longer (2.24 Å) Mg(4)-N(1) bond length. There is one shorter (2.14 Å) and one longer (2.20 Å) Mg(4)-N(4) bond length. Ir(1) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), one N(3), and one N(4) atom. The Ir(1)-N(1) bond length is 2.09 Å. The Ir(1)-N(2) bond length is 1.82 Å. The Ir(1)-N(3) bond length is 2.09 Å. The Ir(1)-N(4) bond length is 2.07 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(3)Mg5Ir octahedra, corners with two equivalent N(4)Mg5Ir octahedra, corners with two equivalent N(2)Mg3Ir tetrahedra, edges with two equivalent N(1)Mg5Ir octahedra, edges with two equivalent N(3)Mg5Ir octahedra, and edges with four equivalent N(4)Mg5Ir octahedra. The corner-sharing octahedral tilt angles range from 8-12°. In the second N site, N(2) is bonded to one Mg(1), two equivalent Mg(2), and one Ir(1) atom to form NMg3Ir tetrahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with two equivalent N(4)Mg5Ir octahedra, corners with six equivalent N(3)Mg5Ir octahedra, and  an edgeedge with one N(2)Mg3Ir tetrahedra. The corner-sharing octahedral tilt angles range from 51-69°. In the third N site, N(3) is bonded to one Mg(1), one Mg(3), one Mg(4), two equivalent Mg(2), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with six equivalent N(2)Mg3Ir tetrahedra,  an edgeedge with one N(3)Mg5Ir octahedra, edges with two equivalent N(1)Mg5Ir octahedra, and edges with three equivalent N(4)Mg5Ir octahedra. The corner-sharing octahedral tilt angles are 8°. In the fourth N site, N(4) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Ir(1) atom to form NMg5Ir octahedra that share corners with two equivalent N(1)Mg5Ir octahedra, corners with two equivalent N(2)Mg3Ir tetrahedra, edges with two equivalent N(4)Mg5Ir octahedra, edges with three equivalent N(3)Mg5Ir octahedra, and edges with four equivalent N(1)Mg5Ir octahedra. The corner-sharing octahedral tilt angles are 12°.