Mg3Ga3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted see-saw-like geometry to one N(3), one N(4), and two equivalent N(2) atoms. In the second Mg site, Mg(2) is bonded to one N(3), two equivalent N(1), and two equivalent N(5) atoms to form distorted MgN5 trigonal bipyramids that share corners with two equivalent Ga(1)N4 tetrahedra, corners with two equivalent Ga(2)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra,  an edgeedge with one Ga(3)N4 tetrahedra, edges with two equivalent Ga(1)N4 tetrahedra, and edges with two equivalent Mg(2)N5 trigonal bipyramids. In the third Mg site, Mg(3) is bonded in a distorted trigonal non-coplanar geometry to one N(2), one N(3), and one N(5) atom. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one N(1), one N(5), and two equivalent N(3) atoms to form GaN4 tetrahedra that share  a cornercorner with one Ga(2)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(1)N4 tetrahedra, and edges with two equivalent Mg(2)N5 trigonal bipyramids. In the second Ga site, Ga(2) is bonded to one N(1), one N(2), and two equivalent N(4) atoms to form distorted GaN4 tetrahedra that share  a cornercorner with one Ga(1)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(2)N4 tetrahedra, and  an edgeedge with one Ga(3)N4 tetrahedra. In the third Ga site, Ga(3) is bonded to one N(1), one N(2), one N(4), and one N(5) atom to form distorted GaN4 tetrahedra that share corners with two equivalent Ga(1)N4 tetrahedra, corners with two equivalent Ga(2)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(2)N4 tetrahedra, and  an edgeedge with one Mg(2)N5 trigonal bipyramid. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Mg(2), one Ga(1), one Ga(2), and one Ga(3) atom to form distorted NMg2Ga3 square pyramids that share corners with three equivalent N(4)MgGa3 tetrahedra, corners with two equivalent N(5)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(1)Mg2Ga3 square pyramid,  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid, and edges with two equivalent N(5)Mg3Ga2 trigonal bipyramids. In the second N site, N(2) is bonded to one Mg(3), two equivalent Mg(1), one Ga(2), and one Ga(3) atom to form distorted NMg3Ga2 trigonal bipyramids that share corners with three equivalent N(4)MgGa3 tetrahedra, corners with two equivalent N(5)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(1)Mg2Ga3 square pyramid,  an edgeedge with one N(4)MgGa3 tetrahedra, and  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid. In the third N site, N(3) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), and two equivalent Ga(1) atoms. In the fourth N site, N(4) is bonded to one Mg(1), one Ga(3), and two equivalent Ga(2) atoms to form distorted NMgGa3 tetrahedra that share corners with three equivalent N(1)Mg2Ga3 square pyramids,  a cornercorner with one N(5)Mg3Ga2 trigonal bipyramid, corners with three equivalent N(2)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(4)MgGa3 tetrahedra, and  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid. In the fifth N site, N(5) is bonded to one Mg(3), two equivalent Mg(2), one Ga(1), and one Ga(3) atom to form NMg3Ga2 trigonal bipyramids that share corners with two equivalent N(1)Mg2Ga3 square pyramids,  a cornercorner with one N(4)MgGa3 tetrahedra, corners with two equivalent N(2)Mg3Ga2 trigonal bipyramids, edges with two equivalent N(1)Mg2Ga3 square pyramids, and  an edgeedge with one N(5)Mg3Ga2 trigonal bipyramid.
Mg3Ga3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted see-saw-like geometry to one N(3), one N(4), and two equivalent N(2) atoms. The Mg(1)-N(3) bond length is 2.10 Å. The Mg(1)-N(4) bond length is 2.11 Å. There is one shorter (2.14 Å) and one longer (2.20 Å) Mg(1)-N(2) bond length. In the second Mg site, Mg(2) is bonded to one N(3), two equivalent N(1), and two equivalent N(5) atoms to form distorted MgN5 trigonal bipyramids that share corners with two equivalent Ga(1)N4 tetrahedra, corners with two equivalent Ga(2)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra,  an edgeedge with one Ga(3)N4 tetrahedra, edges with two equivalent Ga(1)N4 tetrahedra, and edges with two equivalent Mg(2)N5 trigonal bipyramids. The Mg(2)-N(3) bond length is 2.38 Å. There is one shorter (2.17 Å) and one longer (2.26 Å) Mg(2)-N(1) bond length. There is one shorter (2.15 Å) and one longer (2.35 Å) Mg(2)-N(5) bond length. In the third Mg site, Mg(3) is bonded in a distorted trigonal non-coplanar geometry to one N(2), one N(3), and one N(5) atom. The Mg(3)-N(2) bond length is 2.05 Å. The Mg(3)-N(3) bond length is 2.05 Å. The Mg(3)-N(5) bond length is 2.06 Å. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one N(1), one N(5), and two equivalent N(3) atoms to form GaN4 tetrahedra that share  a cornercorner with one Ga(2)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(1)N4 tetrahedra, and edges with two equivalent Mg(2)N5 trigonal bipyramids. The Ga(1)-N(1) bond length is 1.97 Å. The Ga(1)-N(5) bond length is 1.96 Å. There is one shorter (1.97 Å) and one longer (2.05 Å) Ga(1)-N(3) bond length. In the second Ga site, Ga(2) is bonded to one N(1), one N(2), and two equivalent N(4) atoms to form distorted GaN4 tetrahedra that share  a cornercorner with one Ga(1)N4 tetrahedra, corners with two equivalent Ga(3)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(2)N4 tetrahedra, and  an edgeedge with one Ga(3)N4 tetrahedra. The Ga(2)-N(1) bond length is 1.98 Å. The Ga(2)-N(2) bond length is 1.98 Å. There is one shorter (1.93 Å) and one longer (1.96 Å) Ga(2)-N(4) bond length. In the third Ga site, Ga(3) is bonded to one N(1), one N(2), one N(4), and one N(5) atom to form distorted GaN4 tetrahedra that share corners with two equivalent Ga(1)N4 tetrahedra, corners with two equivalent Ga(2)N4 tetrahedra, corners with two equivalent Mg(2)N5 trigonal bipyramids,  an edgeedge with one Ga(2)N4 tetrahedra, and  an edgeedge with one Mg(2)N5 trigonal bipyramid. The Ga(3)-N(1) bond length is 2.00 Å. The Ga(3)-N(2) bond length is 2.09 Å. The Ga(3)-N(4) bond length is 1.90 Å. The Ga(3)-N(5) bond length is 1.96 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Mg(2), one Ga(1), one Ga(2), and one Ga(3) atom to form distorted NMg2Ga3 square pyramids that share corners with three equivalent N(4)MgGa3 tetrahedra, corners with two equivalent N(5)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(1)Mg2Ga3 square pyramid,  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid, and edges with two equivalent N(5)Mg3Ga2 trigonal bipyramids. In the second N site, N(2) is bonded to one Mg(3), two equivalent Mg(1), one Ga(2), and one Ga(3) atom to form distorted NMg3Ga2 trigonal bipyramids that share corners with three equivalent N(4)MgGa3 tetrahedra, corners with two equivalent N(5)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(1)Mg2Ga3 square pyramid,  an edgeedge with one N(4)MgGa3 tetrahedra, and  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid. In the third N site, N(3) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), and two equivalent Ga(1) atoms. In the fourth N site, N(4) is bonded to one Mg(1), one Ga(3), and two equivalent Ga(2) atoms to form distorted NMgGa3 tetrahedra that share corners with three equivalent N(1)Mg2Ga3 square pyramids,  a cornercorner with one N(5)Mg3Ga2 trigonal bipyramid, corners with three equivalent N(2)Mg3Ga2 trigonal bipyramids,  an edgeedge with one N(4)MgGa3 tetrahedra, and  an edgeedge with one N(2)Mg3Ga2 trigonal bipyramid. In the fifth N site, N(5) is bonded to one Mg(3), two equivalent Mg(2), one Ga(1), and one Ga(3) atom to form NMg3Ga2 trigonal bipyramids that share corners with two equivalent N(1)Mg2Ga3 square pyramids,  a cornercorner with one N(4)MgGa3 tetrahedra, corners with two equivalent N(2)Mg3Ga2 trigonal bipyramids, edges with two equivalent N(1)Mg2Ga3 square pyramids, and  an edgeedge with one N(5)Mg3Ga2 trigonal bipyramid.