The structure described by MgY2S4 crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with three equivalent Y(2)S6 octahedra, corners with four equivalent Y(1)S7 pentagonal bipyramids, edges with two equivalent Mg(1)S6 octahedra, edges with three equivalent Y(2)S6 octahedra, and edges with three equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted YS7 pentagonal bipyramids that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Y(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, edges with three equivalent Y(2)S6 octahedra, and faces with two equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 17-66°. In the second Y site, Y(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form YS6 octahedra that share corners with three equivalent Mg(1)S6 octahedra, corners with four equivalent Y(1)S7 pentagonal bipyramids, edges with two equivalent Y(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and edges with three equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are four inequivalent S sites. In the first S site, S(1) 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(3)Y3Mg2 square pyramids, corners with six equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(4)Y3Mg tetrahedra,  an edgeedge with one S(2)Y3Mg2 square pyramid, edges with three equivalent S(3)Y3Mg2 square pyramids,  an edgeedge with one S(4)Y3Mg tetrahedra, and edges with two equivalent S(1)Y4Mg trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Mg(1), one Y(1), and two equivalent Y(2) atoms to form SY3Mg2 square pyramids that share corners with two equivalent S(3)Y3Mg2 square pyramids, corners with two equivalent S(4)Y3Mg tetrahedra, corners with six equivalent S(1)Y4Mg trigonal bipyramids, edges with two equivalent S(2)Y3Mg2 square pyramids, edges with three equivalent S(3)Y3Mg2 square pyramids, edges with two equivalent S(4)Y3Mg tetrahedra, and  an edgeedge with one S(1)Y4Mg trigonal bipyramid. In the third S site, S(3) is bonded to two equivalent Mg(1), one Y(2), and two equivalent Y(1) atoms to form SY3Mg2 square pyramids that share corners with two equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(4)Y3Mg tetrahedra, corners with two equivalent S(1)Y4Mg trigonal bipyramids, edges with two equivalent S(3)Y3Mg2 square pyramids, edges with three equivalent S(2)Y3Mg2 square pyramids,  an edgeedge with one S(4)Y3Mg tetrahedra, and edges with three equivalent S(1)Y4Mg trigonal bipyramids. In the fourth S site, S(4) is bonded to one Mg(1), one Y(2), and two equivalent Y(1) atoms to form SY3Mg tetrahedra that share corners with two equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(3)Y3Mg2 square pyramids, corners with two equivalent S(4)Y3Mg tetrahedra, corners with five equivalent S(1)Y4Mg trigonal bipyramids,  an edgeedge with one S(3)Y3Mg2 square pyramid, edges with two equivalent S(2)Y3Mg2 square pyramids, and  an edgeedge with one S(1)Y4Mg trigonal bipyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.519
_cell_length_b   6.519
_cell_length_c   12.845
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.262
_symmetry_Int_Tables_number   1
_cell_volume   303.183
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Y  Y0  1  0.382  0.618  0.785  1.0
  Y  Y1  1  0.618  0.382  0.285  1.0
  Y  Y2  1  0.138  0.862  0.583  1.0
  Y  Y3  1  0.862  0.138  0.083  1.0
  Mg  Mg4  1  0.126  0.874  0.946  1.0
  Mg  Mg5  1  0.874  0.126  0.446  1.0
  S  S6  1  0.789  0.211  0.635  1.0
  S  S7  1  0.211  0.789  0.135  1.0
  S  S8  1  0.488  0.512  0.996  1.0
  S  S9  1  0.512  0.488  0.496  1.0
  S  S10  1  0.761  0.239  0.896  1.0
  S  S11  1  0.239  0.761  0.396  1.0
  S  S12  1  0.037  0.963  0.768  1.0
  S  S13  1  0.963  0.037  0.268  1.0
[/CIF]
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The structure described by MgY2S4 crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with three equivalent Y(2)S6 octahedra, corners with four equivalent Y(1)S7 pentagonal bipyramids, edges with two equivalent Mg(1)S6 octahedra, edges with three equivalent Y(2)S6 octahedra, and edges with three equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one S(2), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form distorted YS7 pentagonal bipyramids that share corners with four equivalent Mg(1)S6 octahedra, corners with four equivalent Y(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, edges with three equivalent Y(2)S6 octahedra, and faces with two equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 17-66°. In the second Y site, Y(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form YS6 octahedra that share corners with three equivalent Mg(1)S6 octahedra, corners with four equivalent Y(1)S7 pentagonal bipyramids, edges with two equivalent Y(2)S6 octahedra, edges with three equivalent Mg(1)S6 octahedra, and edges with three equivalent Y(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 11-54°. There are four inequivalent S sites. In the first S site, S(1) 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(3)Y3Mg2 square pyramids, corners with six equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(4)Y3Mg tetrahedra,  an edgeedge with one S(2)Y3Mg2 square pyramid, edges with three equivalent S(3)Y3Mg2 square pyramids,  an edgeedge with one S(4)Y3Mg tetrahedra, and edges with two equivalent S(1)Y4Mg trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Mg(1), one Y(1), and two equivalent Y(2) atoms to form SY3Mg2 square pyramids that share corners with two equivalent S(3)Y3Mg2 square pyramids, corners with two equivalent S(4)Y3Mg tetrahedra, corners with six equivalent S(1)Y4Mg trigonal bipyramids, edges with two equivalent S(2)Y3Mg2 square pyramids, edges with three equivalent S(3)Y3Mg2 square pyramids, edges with two equivalent S(4)Y3Mg tetrahedra, and  an edgeedge with one S(1)Y4Mg trigonal bipyramid. In the third S site, S(3) is bonded to two equivalent Mg(1), one Y(2), and two equivalent Y(1) atoms to form SY3Mg2 square pyramids that share corners with two equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(4)Y3Mg tetrahedra, corners with two equivalent S(1)Y4Mg trigonal bipyramids, edges with two equivalent S(3)Y3Mg2 square pyramids, edges with three equivalent S(2)Y3Mg2 square pyramids,  an edgeedge with one S(4)Y3Mg tetrahedra, and edges with three equivalent S(1)Y4Mg trigonal bipyramids. In the fourth S site, S(4) is bonded to one Mg(1), one Y(2), and two equivalent Y(1) atoms to form SY3Mg tetrahedra that share corners with two equivalent S(2)Y3Mg2 square pyramids, corners with five equivalent S(3)Y3Mg2 square pyramids, corners with two equivalent S(4)Y3Mg tetrahedra, corners with five equivalent S(1)Y4Mg trigonal bipyramids,  an edgeedge with one S(3)Y3Mg2 square pyramid, edges with two equivalent S(2)Y3Mg2 square pyramids, and  an edgeedge with one S(1)Y4Mg trigonal bipyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Y2MgS4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.519
_cell_length_b   6.519
_cell_length_c   12.845
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.262
_symmetry_Int_Tables_number   1
_cell_volume   303.183
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Y  Y0  1  0.382  0.618  0.785  1.0
  Y  Y1  1  0.618  0.382  0.285  1.0
  Y  Y2  1  0.138  0.862  0.583  1.0
  Y  Y3  1  0.862  0.138  0.083  1.0
  Mg  Mg4  1  0.126  0.874  0.946  1.0
  Mg  Mg5  1  0.874  0.126  0.446  1.0
  S  S6  1  0.789  0.211  0.635  1.0
  S  S7  1  0.211  0.789  0.135  1.0
  S  S8  1  0.488  0.512  0.996  1.0
  S  S9  1  0.512  0.488  0.496  1.0
  S  S10  1  0.761  0.239  0.896  1.0
  S  S11  1  0.239  0.761  0.396  1.0
  S  S12  1  0.037  0.963  0.768  1.0
  S  S13  1  0.963  0.037  0.268  1.0
[/CIF]
.