MgPm2S4 is Aluminum carbonitride-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one S(2), one S(3), one S(5), and one S(6) atom to form MgS4 tetrahedra that share  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Pm(2)S6 octahedra, corners with three equivalent Pm(1)S5 trigonal bipyramids, corners with three equivalent Pm(3)S5 trigonal bipyramids, and corners with three equivalent Pm(4)S5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 62-66°. In the second Mg site, Mg(2) is bonded to one S(2), one S(7), two equivalent S(1), and two equivalent S(8) atoms to form distorted MgS6 octahedra that share  a cornercorner with one Mg(1)S4 tetrahedra,  a cornercorner with one Pm(4)S5 trigonal bipyramid, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(3)S5 trigonal bipyramids, edges with two equivalent Mg(2)S6 octahedra, and edges with four equivalent Pm(2)S6 octahedra. There are four inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to one S(1), one S(3), one S(4), one S(5), and one S(6) atom to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Pm(2)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(3)S5 trigonal bipyramids, corners with two equivalent Pm(4)S5 trigonal bipyramids,  an edgeedge with one Pm(3)S5 trigonal bipyramid, and  an edgeedge with one Pm(4)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 62-64°. In the second Pm site, Pm(2) is bonded to one S(1), one S(8), two equivalent S(2), and two equivalent S(7) atoms to form distorted PmS6 octahedra that share corners with two equivalent Mg(1)S4 tetrahedra,  a cornercorner with one Pm(1)S5 trigonal bipyramid,  a cornercorner with one Pm(3)S5 trigonal bipyramid, corners with two equivalent Pm(4)S5 trigonal bipyramids, edges with two equivalent Pm(2)S6 octahedra, and edges with four equivalent Mg(2)S6 octahedra. In the third Pm site, Pm(3) is bonded to one S(3), one S(4), one S(8), and two equivalent S(6) atoms to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Pm(2)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(4)S5 trigonal bipyramids,  an edgeedge with one Pm(1)S5 trigonal bipyramid, and  an edgeedge with one Pm(3)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 58-67°. In the fourth Pm site, Pm(4) is bonded to one S(3), one S(4), one S(7), and two equivalent S(5) atoms to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Pm(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(3)S5 trigonal bipyramids,  an edgeedge with one Pm(1)S5 trigonal bipyramid, and  an edgeedge with one Pm(4)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 61-64°. There are eight inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Mg(2), one Pm(1), and one Pm(2) atom to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra,  a cornercorner with one S(5)Pm3Mg tetrahedra,  a cornercorner with one S(6)Pm3Mg tetrahedra, corners with two equivalent S(2)Pm2Mg2 tetrahedra, corners with three equivalent S(8)Pm2Mg2 tetrahedra, corners with four equivalent S(7)Pm3Mg tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra, and  an edgeedge with one S(8)Pm2Mg2 tetrahedra. In the second S site, S(2) is bonded to one Mg(1), one Mg(2), and two equivalent Pm(2) atoms to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra,  a cornercorner with one S(5)Pm3Mg tetrahedra,  a cornercorner with one S(6)Pm3Mg tetrahedra, corners with two equivalent S(1)Pm2Mg2 tetrahedra, corners with three equivalent S(7)Pm3Mg tetrahedra, corners with four equivalent S(8)Pm2Mg2 tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra. In the third S site, S(3) is bonded to one Mg(1), one Pm(1), one Pm(3), and one Pm(4) atom to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra,  a cornercorner with one S(8)Pm2Mg2 tetrahedra,  a cornercorner with one S(7)Pm3Mg tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra,  an edgeedge with one S(5)Pm3Mg tetrahedra, and  an edgeedge with one S(6)Pm3Mg tetrahedra. In the fourth S site, S(4) is bonded in a trigonal planar geometry to one Pm(1), one Pm(3), and one Pm(4) atom. In the fifth S site, S(5) is bonded to one Mg(1), one Pm(1), and two equivalent Pm(4) atoms to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra, corners with two equivalent S(3)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra, corners with two equivalent S(7)Pm3Mg tetrahedra,  an edgeedge with one S(3)Pm3Mg tetrahedra, and  an edgeedge with one S(5)Pm3Mg tetrahedra. In the sixth S site, S(6) is bonded to one Mg(1), one Pm(1), and two equivalent Pm(3) atoms to form SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra, corners with two equivalent S(8)Pm2Mg2 tetrahedra, corners with two equivalent S(3)Pm3Mg tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra,  an edgeedge with one S(3)Pm3Mg tetrahedra, and  an edgeedge with one S(6)Pm3Mg tetrahedra. In the seventh S site, S(7) is bonded to one Mg(2), one Pm(4), and two equivalent Pm(2) atoms to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra, corners with two equivalent S(8)Pm2Mg2 tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra, corners with three equivalent S(2)Pm2Mg2 tetrahedra, corners with four equivalent S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra,  an edgeedge with one S(8)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra. In the eighth S site, S(8) is bonded to two equivalent Mg(2), one Pm(2), and one Pm(3) atom to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra, corners with two equivalent S(7)Pm3Mg tetrahedra, corners with three equivalent S(1)Pm2Mg2 tetrahedra, corners with four equivalent S(2)Pm2Mg2 tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(8)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra.
MgPm2S4 is Aluminum carbonitride-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one S(2), one S(3), one S(5), and one S(6) atom to form MgS4 tetrahedra that share  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Pm(2)S6 octahedra, corners with three equivalent Pm(1)S5 trigonal bipyramids, corners with three equivalent Pm(3)S5 trigonal bipyramids, and corners with three equivalent Pm(4)S5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 62-66°. The Mg(1)-S(2) bond length is 2.40 Å. The Mg(1)-S(3) bond length is 2.48 Å. The Mg(1)-S(5) bond length is 2.51 Å. The Mg(1)-S(6) bond length is 2.48 Å. In the second Mg site, Mg(2) is bonded to one S(2), one S(7), two equivalent S(1), and two equivalent S(8) atoms to form distorted MgS6 octahedra that share  a cornercorner with one Mg(1)S4 tetrahedra,  a cornercorner with one Pm(4)S5 trigonal bipyramid, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(3)S5 trigonal bipyramids, edges with two equivalent Mg(2)S6 octahedra, and edges with four equivalent Pm(2)S6 octahedra. The Mg(2)-S(2) bond length is 2.74 Å. The Mg(2)-S(7) bond length is 3.04 Å. There is one shorter (2.72 Å) and one longer (2.86 Å) Mg(2)-S(1) bond length. There is one shorter (2.73 Å) and one longer (2.75 Å) Mg(2)-S(8) bond length. There are four inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to one S(1), one S(3), one S(4), one S(5), and one S(6) atom to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Pm(2)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(3)S5 trigonal bipyramids, corners with two equivalent Pm(4)S5 trigonal bipyramids,  an edgeedge with one Pm(3)S5 trigonal bipyramid, and  an edgeedge with one Pm(4)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 62-64°. The Pm(1)-S(1) bond length is 2.65 Å. The Pm(1)-S(3) bond length is 3.07 Å. The Pm(1)-S(4) bond length is 2.64 Å. The Pm(1)-S(5) bond length is 2.73 Å. The Pm(1)-S(6) bond length is 2.71 Å. In the second Pm site, Pm(2) is bonded to one S(1), one S(8), two equivalent S(2), and two equivalent S(7) atoms to form distorted PmS6 octahedra that share corners with two equivalent Mg(1)S4 tetrahedra,  a cornercorner with one Pm(1)S5 trigonal bipyramid,  a cornercorner with one Pm(3)S5 trigonal bipyramid, corners with two equivalent Pm(4)S5 trigonal bipyramids, edges with two equivalent Pm(2)S6 octahedra, and edges with four equivalent Mg(2)S6 octahedra. The Pm(2)-S(1) bond length is 2.86 Å. The Pm(2)-S(8) bond length is 2.92 Å. There is one shorter (2.89 Å) and one longer (2.92 Å) Pm(2)-S(2) bond length. Both Pm(2)-S(7) bond lengths are 2.88 Å. In the third Pm site, Pm(3) is bonded to one S(3), one S(4), one S(8), and two equivalent S(6) atoms to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Pm(2)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(4)S5 trigonal bipyramids,  an edgeedge with one Pm(1)S5 trigonal bipyramid, and  an edgeedge with one Pm(3)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 58-67°. The Pm(3)-S(3) bond length is 2.70 Å. The Pm(3)-S(4) bond length is 2.64 Å. The Pm(3)-S(8) bond length is 2.66 Å. There is one shorter (2.69 Å) and one longer (3.09 Å) Pm(3)-S(6) bond length. In the fourth Pm site, Pm(4) is bonded to one S(3), one S(4), one S(7), and two equivalent S(5) atoms to form distorted PmS5 trigonal bipyramids that share  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Pm(2)S6 octahedra, corners with three equivalent Mg(1)S4 tetrahedra, corners with two equivalent Pm(1)S5 trigonal bipyramids, corners with two equivalent Pm(3)S5 trigonal bipyramids,  an edgeedge with one Pm(1)S5 trigonal bipyramid, and  an edgeedge with one Pm(4)S5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 61-64°. The Pm(4)-S(3) bond length is 2.68 Å. The Pm(4)-S(4) bond length is 2.63 Å. The Pm(4)-S(7) bond length is 2.65 Å. There is one shorter (2.71 Å) and one longer (3.06 Å) Pm(4)-S(5) bond length. There are eight inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Mg(2), one Pm(1), and one Pm(2) atom to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra,  a cornercorner with one S(5)Pm3Mg tetrahedra,  a cornercorner with one S(6)Pm3Mg tetrahedra, corners with two equivalent S(2)Pm2Mg2 tetrahedra, corners with three equivalent S(8)Pm2Mg2 tetrahedra, corners with four equivalent S(7)Pm3Mg tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra, and  an edgeedge with one S(8)Pm2Mg2 tetrahedra. In the second S site, S(2) is bonded to one Mg(1), one Mg(2), and two equivalent Pm(2) atoms to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra,  a cornercorner with one S(5)Pm3Mg tetrahedra,  a cornercorner with one S(6)Pm3Mg tetrahedra, corners with two equivalent S(1)Pm2Mg2 tetrahedra, corners with three equivalent S(7)Pm3Mg tetrahedra, corners with four equivalent S(8)Pm2Mg2 tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra. In the third S site, S(3) is bonded to one Mg(1), one Pm(1), one Pm(3), and one Pm(4) atom to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra,  a cornercorner with one S(8)Pm2Mg2 tetrahedra,  a cornercorner with one S(7)Pm3Mg tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra,  an edgeedge with one S(5)Pm3Mg tetrahedra, and  an edgeedge with one S(6)Pm3Mg tetrahedra. In the fourth S site, S(4) is bonded in a trigonal planar geometry to one Pm(1), one Pm(3), and one Pm(4) atom. In the fifth S site, S(5) is bonded to one Mg(1), one Pm(1), and two equivalent Pm(4) atoms to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra, corners with two equivalent S(3)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra, corners with two equivalent S(7)Pm3Mg tetrahedra,  an edgeedge with one S(3)Pm3Mg tetrahedra, and  an edgeedge with one S(5)Pm3Mg tetrahedra. In the sixth S site, S(6) is bonded to one Mg(1), one Pm(1), and two equivalent Pm(3) atoms to form SPm3Mg tetrahedra that share  a cornercorner with one S(1)Pm2Mg2 tetrahedra,  a cornercorner with one S(2)Pm2Mg2 tetrahedra, corners with two equivalent S(8)Pm2Mg2 tetrahedra, corners with two equivalent S(3)Pm3Mg tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra,  an edgeedge with one S(3)Pm3Mg tetrahedra, and  an edgeedge with one S(6)Pm3Mg tetrahedra. In the seventh S site, S(7) is bonded to one Mg(2), one Pm(4), and two equivalent Pm(2) atoms to form distorted SPm3Mg tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra, corners with two equivalent S(8)Pm2Mg2 tetrahedra, corners with two equivalent S(5)Pm3Mg tetrahedra, corners with three equivalent S(2)Pm2Mg2 tetrahedra, corners with four equivalent S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(2)Pm2Mg2 tetrahedra,  an edgeedge with one S(8)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra. In the eighth S site, S(8) is bonded to two equivalent Mg(2), one Pm(2), and one Pm(3) atom to form SPm2Mg2 tetrahedra that share  a cornercorner with one S(3)Pm3Mg tetrahedra, corners with two equivalent S(6)Pm3Mg tetrahedra, corners with two equivalent S(7)Pm3Mg tetrahedra, corners with three equivalent S(1)Pm2Mg2 tetrahedra, corners with four equivalent S(2)Pm2Mg2 tetrahedra,  an edgeedge with one S(1)Pm2Mg2 tetrahedra,  an edgeedge with one S(8)Pm2Mg2 tetrahedra, and  an edgeedge with one S(7)Pm3Mg tetrahedra.