SrMgP3N5O2 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 9-coordinate geometry to one N(2), one N(3), two equivalent N(4), two equivalent N(5), one O(1), and two equivalent O(2) atoms. Mg(1) is bonded to one N(1), one N(2), one N(3), one O(2), and two equivalent O(1) atoms to form distorted MgN3O3 octahedra that share  a cornercorner with one P(2)N3O tetrahedra,  a cornercorner with one P(3)N3O tetrahedra, corners with three equivalent P(1)N4 tetrahedra,  an edgeedge with one Mg(1)N3O3 octahedra,  an edgeedge with one P(2)N3O tetrahedra, and  an edgeedge with one P(3)N3O tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one N(1), one N(2), one N(3), and one N(5) atom to form PN4 tetrahedra that share corners with three equivalent Mg(1)N3O3 octahedra, corners with two equivalent P(2)N3O tetrahedra, and corners with two equivalent P(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 48-61°. In the second P site, P(2) is bonded to one N(1), one N(4), one N(5), and one O(1) atom to form PN3O tetrahedra that share  a cornercorner with one Mg(1)N3O3 octahedra,  a cornercorner with one P(3)N3O tetrahedra, corners with two equivalent P(1)N4 tetrahedra, and  an edgeedge with one Mg(1)N3O3 octahedra. The corner-sharing octahedral tilt angles are 62°. In the third P site, P(3) is bonded to one N(2), one N(3), one N(4), and one O(2) atom to form PN3O tetrahedra that share  a cornercorner with one Mg(1)N3O3 octahedra,  a cornercorner with one P(2)N3O tetrahedra, corners with two equivalent P(1)N4 tetrahedra, and  an edgeedge with one Mg(1)N3O3 octahedra. The corner-sharing octahedral tilt angles are 58°. There are five inequivalent N sites. In the first N site, N(4) is bonded in a 3-coordinate geometry to two equivalent Sr(1), one P(2), and one P(3) atom. In the second N site, N(5) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one P(1), and one P(2) atom. In the third N site, N(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one P(1), and one P(2) atom. In the fourth N site, N(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), one P(1), and one P(3) atom. In the fifth N site, N(3) is bonded in a distorted tetrahedral geometry to one Sr(1), one Mg(1), one P(1), and one P(3) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Mg(1), and one P(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Mg(1), and one P(3) atom.
SrMgP3N5O2 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 9-coordinate geometry to one N(2), one N(3), two equivalent N(4), two equivalent N(5), one O(1), and two equivalent O(2) atoms. The Sr(1)-N(2) bond length is 3.10 Å. The Sr(1)-N(3) bond length is 2.76 Å. There is one shorter (2.63 Å) and one longer (3.24 Å) Sr(1)-N(4) bond length. There is one shorter (2.67 Å) and one longer (3.02 Å) Sr(1)-N(5) bond length. The Sr(1)-O(1) bond length is 2.60 Å. There is one shorter (2.73 Å) and one longer (3.18 Å) Sr(1)-O(2) bond length. Mg(1) is bonded to one N(1), one N(2), one N(3), one O(2), and two equivalent O(1) atoms to form distorted MgN3O3 octahedra that share  a cornercorner with one P(2)N3O tetrahedra,  a cornercorner with one P(3)N3O tetrahedra, corners with three equivalent P(1)N4 tetrahedra,  an edgeedge with one Mg(1)N3O3 octahedra,  an edgeedge with one P(2)N3O tetrahedra, and  an edgeedge with one P(3)N3O tetrahedra. The Mg(1)-N(1) bond length is 2.10 Å. The Mg(1)-N(2) bond length is 2.16 Å. The Mg(1)-N(3) bond length is 2.37 Å. The Mg(1)-O(2) bond length is 2.05 Å. There is one shorter (2.10 Å) and one longer (2.31 Å) Mg(1)-O(1) bond length. There are three inequivalent P sites. In the first P site, P(1) is bonded to one N(1), one N(2), one N(3), and one N(5) atom to form PN4 tetrahedra that share corners with three equivalent Mg(1)N3O3 octahedra, corners with two equivalent P(2)N3O tetrahedra, and corners with two equivalent P(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 48-61°. The P(1)-N(1) bond length is 1.63 Å. The P(1)-N(2) bond length is 1.64 Å. The P(1)-N(3) bond length is 1.64 Å. The P(1)-N(5) bond length is 1.65 Å. In the second P site, P(2) is bonded to one N(1), one N(4), one N(5), and one O(1) atom to form PN3O tetrahedra that share  a cornercorner with one Mg(1)N3O3 octahedra,  a cornercorner with one P(3)N3O tetrahedra, corners with two equivalent P(1)N4 tetrahedra, and  an edgeedge with one Mg(1)N3O3 octahedra. The corner-sharing octahedral tilt angles are 62°. The P(2)-N(1) bond length is 1.63 Å. The P(2)-N(4) bond length is 1.63 Å. The P(2)-N(5) bond length is 1.63 Å. The P(2)-O(1) bond length is 1.58 Å. In the third P site, P(3) is bonded to one N(2), one N(3), one N(4), and one O(2) atom to form PN3O tetrahedra that share  a cornercorner with one Mg(1)N3O3 octahedra,  a cornercorner with one P(2)N3O tetrahedra, corners with two equivalent P(1)N4 tetrahedra, and  an edgeedge with one Mg(1)N3O3 octahedra. The corner-sharing octahedral tilt angles are 58°. The P(3)-N(2) bond length is 1.65 Å. The P(3)-N(3) bond length is 1.65 Å. The P(3)-N(4) bond length is 1.63 Å. The P(3)-O(2) bond length is 1.56 Å. There are five inequivalent N sites. In the first N site, N(4) is bonded in a 3-coordinate geometry to two equivalent Sr(1), one P(2), and one P(3) atom. In the second N site, N(5) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one P(1), and one P(2) atom. In the third N site, N(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one P(1), and one P(2) atom. In the fourth N site, N(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), one P(1), and one P(3) atom. In the fifth N site, N(3) is bonded in a distorted tetrahedral geometry to one Sr(1), one Mg(1), one P(1), and one P(3) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Mg(1), and one P(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Mg(1), and one P(3) atom.