MgP6(N3H)4 crystallizes in the orthorhombic Cmce space group. Mg(1) is bonded to two equivalent N(4) and four equivalent N(2) atoms to form MgN6 octahedra that share corners with twelve equivalent P(1)N4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one N(1), one N(4), and two equivalent N(2) atoms to form PN4 tetrahedra that share corners with three equivalent Mg(1)N6 octahedra,  a cornercorner with one P(2)N4 tetrahedra, and corners with three equivalent P(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-62°. In the second P site, P(2) is bonded to two equivalent N(1) and two equivalent N(3) atoms to form corner-sharing PN4 tetrahedra. There are four inequivalent N sites. In the first N site, N(4) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent P(1) atoms. In the second N site, N(1) is bonded in a distorted trigonal planar geometry to one P(1), one P(2), and one H(1) atom. In the third N site, N(3) is bonded in a distorted bent 150 degrees geometry to two equivalent P(2) atoms. In the fourth N site, N(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent P(1) atoms. H(1) is bonded in a single-bond geometry to one N(1) atom.
MgP6(N3H)4 crystallizes in the orthorhombic Cmce space group. Mg(1) is bonded to two equivalent N(4) and four equivalent N(2) atoms to form MgN6 octahedra that share corners with twelve equivalent P(1)N4 tetrahedra. Both Mg(1)-N(4) bond lengths are 2.26 Å. All Mg(1)-N(2) bond lengths are 2.32 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one N(1), one N(4), and two equivalent N(2) atoms to form PN4 tetrahedra that share corners with three equivalent Mg(1)N6 octahedra,  a cornercorner with one P(2)N4 tetrahedra, and corners with three equivalent P(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-62°. The P(1)-N(1) bond length is 1.70 Å. The P(1)-N(4) bond length is 1.62 Å. There is one shorter (1.62 Å) and one longer (1.63 Å) P(1)-N(2) bond length. In the second P site, P(2) is bonded to two equivalent N(1) and two equivalent N(3) atoms to form corner-sharing PN4 tetrahedra. Both P(2)-N(1) bond lengths are 1.67 Å. There is one shorter (1.60 Å) and one longer (1.62 Å) P(2)-N(3) bond length. There are four inequivalent N sites. In the first N site, N(4) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent P(1) atoms. In the second N site, N(1) is bonded in a distorted trigonal planar geometry to one P(1), one P(2), and one H(1) atom. The N(1)-H(1) bond length is 1.03 Å. In the third N site, N(3) is bonded in a distorted bent 150 degrees geometry to two equivalent P(2) atoms. In the fourth N site, N(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent P(1) atoms. H(1) is bonded in a single-bond geometry to one N(1) atom.