Li4Mg(NH)3 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one N(1) and three equivalent N(2) atoms to form LiN4 tetrahedra that share  a cornercorner with one Mg(1)N4 tetrahedra, corners with seven equivalent Li(1)N4 tetrahedra, and edges with two equivalent Mg(1)N4 tetrahedra. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one N(2), one H(1), and two equivalent H(2) atoms. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted MgN4 tetrahedra that share corners with two equivalent Li(1)N4 tetrahedra, corners with two equivalent Mg(1)N4 tetrahedra, and edges with four equivalent Li(1)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted single-bond geometry to two equivalent Li(1), two equivalent Mg(1), and one H(1) atom. In the second N site, N(2) is bonded in a distorted single-bond geometry to one Li(2), three equivalent Li(1), one Mg(1), and one H(2) atom. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to two equivalent Li(2) and one N(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to two equivalent Li(2) and one N(2) atom.
Li4Mg(NH)3 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one N(1) and three equivalent N(2) atoms to form LiN4 tetrahedra that share  a cornercorner with one Mg(1)N4 tetrahedra, corners with seven equivalent Li(1)N4 tetrahedra, and edges with two equivalent Mg(1)N4 tetrahedra. The Li(1)-N(1) bond length is 2.14 Å. There is one shorter (2.14 Å) and two longer (2.17 Å) Li(1)-N(2) bond lengths. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one N(2), one H(1), and two equivalent H(2) atoms. The Li(2)-N(2) bond length is 1.98 Å. The Li(2)-H(1) bond length is 1.96 Å. Both Li(2)-H(2) bond lengths are 2.06 Å. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted MgN4 tetrahedra that share corners with two equivalent Li(1)N4 tetrahedra, corners with two equivalent Mg(1)N4 tetrahedra, and edges with four equivalent Li(1)N4 tetrahedra. Both Mg(1)-N(1) bond lengths are 2.08 Å. Both Mg(1)-N(2) bond lengths are 2.18 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted single-bond geometry to two equivalent Li(1), two equivalent Mg(1), and one H(1) atom. The N(1)-H(1) bond length is 1.03 Å. In the second N site, N(2) is bonded in a distorted single-bond geometry to one Li(2), three equivalent Li(1), one Mg(1), and one H(2) atom. The N(2)-H(2) bond length is 1.03 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to two equivalent Li(2) and one N(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to two equivalent Li(2) and one N(2) atom.