MgY6Si2S14 crystallizes in the trigonal P3 space group. Mg(1) is bonded in an octahedral geometry to three equivalent S(3) and three equivalent S(4) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(3), two equivalent S(4), and two equivalent S(5) atoms. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(3), two equivalent S(4), and two equivalent S(6) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(5) atoms. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one S(2) and three equivalent S(6) atoms. There are six inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Y(1) and one Si(1) atom to form distorted corner-sharing SY3Si tetrahedra. In the second S site, S(2) is bonded to three equivalent Y(2) and one Si(2) atom to form corner-sharing SY3Si tetrahedra. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Y(1), and two equivalent Y(2) atoms. In the fourth S site, S(4) is bonded to one Mg(1), two equivalent Y(1), and two equivalent Y(2) atoms to form distorted SY4Mg trigonal bipyramids that share corners with two equivalent S(1)Y3Si tetrahedra, corners with two equivalent S(2)Y3Si tetrahedra, corners with two equivalent S(4)Y4Mg trigonal bipyramids, and edges with two equivalent S(4)Y4Mg trigonal bipyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Y(2), two equivalent Y(1), and one Si(1) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one Y(1), two equivalent Y(2), and one Si(2) atom.
MgY6Si2S14 crystallizes in the trigonal P3 space group. Mg(1) is bonded in an octahedral geometry to three equivalent S(3) and three equivalent S(4) atoms. All Mg(1)-S(3) bond lengths are 2.57 Å. All Mg(1)-S(4) bond lengths are 2.59 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 8-coordinate geometry to one S(1), one S(6), two equivalent S(3), two equivalent S(4), and two equivalent S(5) atoms. The Y(1)-S(1) bond length is 2.98 Å. The Y(1)-S(6) bond length is 2.95 Å. There is one shorter (2.84 Å) and one longer (3.08 Å) Y(1)-S(3) bond length. There is one shorter (2.77 Å) and one longer (2.79 Å) Y(1)-S(4) bond length. There is one shorter (2.80 Å) and one longer (2.89 Å) Y(1)-S(5) bond length. In the second Y site, Y(2) is bonded in a 8-coordinate geometry to one S(2), one S(5), two equivalent S(3), two equivalent S(4), and two equivalent S(6) atoms. The Y(2)-S(2) bond length is 2.98 Å. The Y(2)-S(5) bond length is 2.93 Å. There is one shorter (2.77 Å) and one longer (2.79 Å) Y(2)-S(3) bond length. There is one shorter (2.92 Å) and one longer (3.00 Å) Y(2)-S(4) bond length. There is one shorter (2.80 Å) and one longer (2.90 Å) Y(2)-S(6) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(5) atoms. The Si(1)-S(1) bond length is 2.10 Å. All Si(1)-S(5) bond lengths are 2.14 Å. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one S(2) and three equivalent S(6) atoms. The Si(2)-S(2) bond length is 2.11 Å. All Si(2)-S(6) bond lengths are 2.14 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Y(1) and one Si(1) atom to form distorted corner-sharing SY3Si tetrahedra. In the second S site, S(2) is bonded to three equivalent Y(2) and one Si(2) atom to form corner-sharing SY3Si tetrahedra. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Y(1), and two equivalent Y(2) atoms. In the fourth S site, S(4) is bonded to one Mg(1), two equivalent Y(1), and two equivalent Y(2) atoms to form distorted SY4Mg trigonal bipyramids that share corners with two equivalent S(1)Y3Si tetrahedra, corners with two equivalent S(2)Y3Si tetrahedra, corners with two equivalent S(4)Y4Mg trigonal bipyramids, and edges with two equivalent S(4)Y4Mg trigonal bipyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Y(2), two equivalent Y(1), and one Si(1) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one Y(1), two equivalent Y(2), and one Si(2) atom.