Mg2Sm3MnS8 is Spinel-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form MgS4 tetrahedra that share corners with three equivalent Sm(1)S6 octahedra, corners with three equivalent Sm(2)S6 octahedra, corners with three equivalent Sm(3)S6 octahedra, and corners with three equivalent Mn(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 49-61°. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(2)S6 octahedra, edges with two equivalent Sm(3)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. In the second Sm site, Sm(2) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(3)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. In the third Sm site, Sm(3) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(2)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. Mn(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms to form MnS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(2)S6 octahedra, and edges with two equivalent Sm(3)S6 octahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(2), one Sm(3), and one Mn(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(3), and one Mn(1) atom. In the third S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(2), and one Sm(3) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(2), and one Mn(1) atom.
Mg2Sm3MnS8 is Spinel-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form MgS4 tetrahedra that share corners with three equivalent Sm(1)S6 octahedra, corners with three equivalent Sm(2)S6 octahedra, corners with three equivalent Sm(3)S6 octahedra, and corners with three equivalent Mn(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 49-61°. The Mg(1)-S(1) bond length is 2.56 Å. The Mg(1)-S(2) bond length is 2.53 Å. The Mg(1)-S(3) bond length is 2.43 Å. The Mg(1)-S(4) bond length is 2.54 Å. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(2)S6 octahedra, edges with two equivalent Sm(3)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. Both Sm(1)-S(2) bond lengths are 2.80 Å. Both Sm(1)-S(3) bond lengths are 2.75 Å. Both Sm(1)-S(4) bond lengths are 2.81 Å. In the second Sm site, Sm(2) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(3)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. Both Sm(2)-S(1) bond lengths are 2.80 Å. Both Sm(2)-S(3) bond lengths are 2.76 Å. Both Sm(2)-S(4) bond lengths are 2.80 Å. In the third Sm site, Sm(3) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form SmS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(2)S6 octahedra, and edges with two equivalent Mn(1)S6 octahedra. Both Sm(3)-S(1) bond lengths are 2.81 Å. Both Sm(3)-S(2) bond lengths are 2.79 Å. Both Sm(3)-S(3) bond lengths are 2.75 Å. Mn(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms to form MnS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Sm(1)S6 octahedra, edges with two equivalent Sm(2)S6 octahedra, and edges with two equivalent Sm(3)S6 octahedra. Both Mn(1)-S(1) bond lengths are 2.55 Å. Both Mn(1)-S(2) bond lengths are 2.59 Å. Both Mn(1)-S(4) bond lengths are 2.57 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(2), one Sm(3), and one Mn(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(3), and one Mn(1) atom. In the third S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(2), and one Sm(3) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Sm(1), one Sm(2), and one Mn(1) atom.