Mg4SnN4 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 distorted MgN4 tetrahedra that share  a cornercorner with one Mg(3)N5 square pyramid, corners with three equivalent Mg(4)N5 square pyramids, corners with four equivalent Sn(1)N4 tetrahedra,  an edgeedge with one Mg(4)N5 square pyramid, and edges with two equivalent Mg(3)N5 square pyramids. 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, corners with three equivalent Sn(1)N4 tetrahedra, edges with two equivalent Mg(3)N5 square pyramids, edges with three equivalent Mg(4)N5 square pyramids,  an edgeedge with one Sn(1)N4 tetrahedra, 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 distorted MgN5 square pyramids that share corners with three equivalent Mg(3)N5 square pyramids,  a cornercorner with one Sn(1)N4 tetrahedra, 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,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Sn(1)N4 tetrahedra. Sn(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form distorted SnN4 tetrahedra that share  a cornercorner with one Mg(4)N5 square pyramid, corners with three equivalent Mg(3)N5 square pyramids, corners with four equivalent Mg(1)N4 tetrahedra,  an edgeedge with one Mg(3)N5 square pyramid, and edges with two equivalent Mg(4)N5 square pyramids. 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 Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(3)Mg5Sn octahedra, corners with two equivalent N(4)Mg5Sn octahedra, corners with two equivalent N(2)Mg3Sn tetrahedra, edges with two equivalent N(1)Mg5Sn octahedra, edges with two equivalent N(3)Mg5Sn octahedra, and edges with four equivalent N(4)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 11-15°. In the second N site, N(2) is bonded to one Mg(1), two equivalent Mg(2), and one Sn(1) atom to form NMg3Sn tetrahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with two equivalent N(4)Mg5Sn octahedra, corners with six equivalent N(3)Mg5Sn octahedra, and  an edgeedge with one N(2)Mg3Sn tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. 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 Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with six equivalent N(2)Mg3Sn tetrahedra,  an edgeedge with one N(3)Mg5Sn octahedra, edges with two equivalent N(1)Mg5Sn octahedra, and edges with three equivalent N(4)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth N site, N(4) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with two equivalent N(2)Mg3Sn tetrahedra, edges with two equivalent N(4)Mg5Sn octahedra, edges with three equivalent N(3)Mg5Sn octahedra, and edges with four equivalent N(1)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 12-15°.
Mg4SnN4 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 distorted MgN4 tetrahedra that share  a cornercorner with one Mg(3)N5 square pyramid, corners with three equivalent Mg(4)N5 square pyramids, corners with four equivalent Sn(1)N4 tetrahedra,  an edgeedge with one Mg(4)N5 square pyramid, and edges with two equivalent Mg(3)N5 square pyramids. The Mg(1)-N(1) bond length is 2.15 Å. The Mg(1)-N(2) bond length is 2.06 Å. The Mg(1)-N(3) bond length is 2.10 Å. The Mg(1)-N(4) bond length is 2.09 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 (2.11 Å) and one longer (2.13 Å) Mg(2)-N(2) bond length. There is one shorter (2.22 Å) and one longer (2.25 Å) Mg(2)-N(3) bond length. 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, corners with three equivalent Sn(1)N4 tetrahedra, edges with two equivalent Mg(3)N5 square pyramids, edges with three equivalent Mg(4)N5 square pyramids,  an edgeedge with one Sn(1)N4 tetrahedra, and edges with two equivalent Mg(1)N4 tetrahedra. The Mg(3)-N(3) bond length is 2.38 Å. There is one shorter (2.21 Å) and one longer (2.26 Å) Mg(3)-N(1) bond length. There is one shorter (2.10 Å) and one longer (2.32 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 distorted MgN5 square pyramids that share corners with three equivalent Mg(3)N5 square pyramids,  a cornercorner with one Sn(1)N4 tetrahedra, 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,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Sn(1)N4 tetrahedra. The Mg(4)-N(3) bond length is 2.27 Å. There is one shorter (2.23 Å) and one longer (2.26 Å) Mg(4)-N(1) bond length. There is one shorter (2.13 Å) and one longer (2.51 Å) Mg(4)-N(4) bond length. Sn(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form distorted SnN4 tetrahedra that share  a cornercorner with one Mg(4)N5 square pyramid, corners with three equivalent Mg(3)N5 square pyramids, corners with four equivalent Mg(1)N4 tetrahedra,  an edgeedge with one Mg(3)N5 square pyramid, and edges with two equivalent Mg(4)N5 square pyramids. The Sn(1)-N(1) bond length is 2.14 Å. The Sn(1)-N(2) bond length is 2.04 Å. The Sn(1)-N(3) bond length is 2.10 Å. The Sn(1)-N(4) bond length is 2.08 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 Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(3)Mg5Sn octahedra, corners with two equivalent N(4)Mg5Sn octahedra, corners with two equivalent N(2)Mg3Sn tetrahedra, edges with two equivalent N(1)Mg5Sn octahedra, edges with two equivalent N(3)Mg5Sn octahedra, and edges with four equivalent N(4)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 11-15°. In the second N site, N(2) is bonded to one Mg(1), two equivalent Mg(2), and one Sn(1) atom to form NMg3Sn tetrahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with two equivalent N(4)Mg5Sn octahedra, corners with six equivalent N(3)Mg5Sn octahedra, and  an edgeedge with one N(2)Mg3Sn tetrahedra. The corner-sharing octahedral tilt angles range from 57-62°. 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 Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with six equivalent N(2)Mg3Sn tetrahedra,  an edgeedge with one N(3)Mg5Sn octahedra, edges with two equivalent N(1)Mg5Sn octahedra, and edges with three equivalent N(4)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth N site, N(4) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Sn(1) atom to form NMg5Sn octahedra that share corners with two equivalent N(1)Mg5Sn octahedra, corners with two equivalent N(2)Mg3Sn tetrahedra, edges with two equivalent N(4)Mg5Sn octahedra, edges with three equivalent N(3)Mg5Sn octahedra, and edges with four equivalent N(1)Mg5Sn octahedra. The corner-sharing octahedral tilt angles range from 12-15°.