SrMg5N4 crystallizes in the orthorhombic Pmmn space group. Sr(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted SrN4 tetrahedra that share corners with four equivalent Mg(2)N4 tetrahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted trigonal planar geometry to one N(1) and two equivalent N(2) atoms. In the second Mg site, Mg(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with four equivalent Sr(1)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Sr(1), one Mg(2), and two equivalent Mg(1) atoms to form NSrMg3 tetrahedra that share corners with eight equivalent N(2)SrMg5 octahedra and corners with two equivalent N(1)SrMg3 tetrahedra. The corner-sharing octahedral tilt angles range from 51-71°. In the second N site, N(2) is bonded to one Sr(1), one Mg(2), and four equivalent Mg(1) atoms to form NSrMg5 octahedra that share corners with two equivalent N(2)SrMg5 octahedra, corners with eight equivalent N(1)SrMg3 tetrahedra, and edges with two equivalent N(2)SrMg5 octahedra. The corner-sharing octahedral tilt angles range from 58-68°.
SrMg5N4 crystallizes in the orthorhombic Pmmn space group. Sr(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted SrN4 tetrahedra that share corners with four equivalent Mg(2)N4 tetrahedra. Both Sr(1)-N(1) bond lengths are 2.35 Å. Both Sr(1)-N(2) bond lengths are 2.61 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted trigonal planar geometry to one N(1) and two equivalent N(2) atoms. The Mg(1)-N(1) bond length is 2.02 Å. Both Mg(1)-N(2) bond lengths are 2.19 Å. In the second Mg site, Mg(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with four equivalent Sr(1)N4 tetrahedra. Both Mg(2)-N(1) bond lengths are 2.06 Å. Both Mg(2)-N(2) bond lengths are 2.31 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Sr(1), one Mg(2), and two equivalent Mg(1) atoms to form NSrMg3 tetrahedra that share corners with eight equivalent N(2)SrMg5 octahedra and corners with two equivalent N(1)SrMg3 tetrahedra. The corner-sharing octahedral tilt angles range from 51-71°. In the second N site, N(2) is bonded to one Sr(1), one Mg(2), and four equivalent Mg(1) atoms to form NSrMg5 octahedra that share corners with two equivalent N(2)SrMg5 octahedra, corners with eight equivalent N(1)SrMg3 tetrahedra, and edges with two equivalent N(2)SrMg5 octahedra. The corner-sharing octahedral tilt angles range from 58-68°.