Mg3(GaN2)2 is Hausmannite-derived structured and crystallizes in the orthorhombic Pnna space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted edge-sharing GaN4 tetrahedra. In the second Ga site, Ga(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted edge-sharing GaN4 trigonal pyramids. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), one Ga(1), and one Ga(2) atom to form distorted NMg4Ga2 octahedra that share corners with three equivalent N(1)Mg4Ga2 octahedra, corners with six equivalent N(2)Mg2Ga2 tetrahedra, edges with two equivalent N(1)Mg4Ga2 octahedra,  an edgeedge with one N(2)Mg2Ga2 tetrahedra, and  a faceface with one N(1)Mg4Ga2 octahedra. The corner-sharing octahedral tilt angles range from 46-71°. In the second N site, N(2) is bonded to two equivalent Mg(1), one Ga(1), and one Ga(2) atom to form NMg2Ga2 tetrahedra that share corners with six equivalent N(1)Mg4Ga2 octahedra, corners with four equivalent N(2)Mg2Ga2 tetrahedra, and  an edgeedge with one N(1)Mg4Ga2 octahedra. The corner-sharing octahedral tilt angles range from 53-80°.
Mg3(GaN2)2 is Hausmannite-derived structured and crystallizes in the orthorhombic Pnna space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. There is one shorter (2.28 Å) and one longer (2.42 Å) Mg(1)-N(1) bond length. Both Mg(1)-N(2) bond lengths are 2.03 Å. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. There are two shorter (2.11 Å) and two longer (2.43 Å) Mg(2)-N(1) bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted edge-sharing GaN4 tetrahedra. Both Ga(1)-N(1) bond lengths are 2.06 Å. Both Ga(1)-N(2) bond lengths are 1.92 Å. In the second Ga site, Ga(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted edge-sharing GaN4 trigonal pyramids. Both Ga(2)-N(1) bond lengths are 2.09 Å. Both Ga(2)-N(2) bond lengths are 1.90 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), one Ga(1), and one Ga(2) atom to form distorted NMg4Ga2 octahedra that share corners with three equivalent N(1)Mg4Ga2 octahedra, corners with six equivalent N(2)Mg2Ga2 tetrahedra, edges with two equivalent N(1)Mg4Ga2 octahedra,  an edgeedge with one N(2)Mg2Ga2 tetrahedra, and  a faceface with one N(1)Mg4Ga2 octahedra. The corner-sharing octahedral tilt angles range from 46-71°. In the second N site, N(2) is bonded to two equivalent Mg(1), one Ga(1), and one Ga(2) atom to form NMg2Ga2 tetrahedra that share corners with six equivalent N(1)Mg4Ga2 octahedra, corners with four equivalent N(2)Mg2Ga2 tetrahedra, and  an edgeedge with one N(1)Mg4Ga2 octahedra. The corner-sharing octahedral tilt angles range from 53-80°.