The compound described by MgGa2S4 crystallizes in the monoclinic C2/c space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with two equivalent Ga(1)S4 tetrahedra, corners with two equivalent Ga(2)S4 tetrahedra, corners with four equivalent Ga(3)S4 tetrahedra, edges with two equivalent Mg(3)S6 octahedra, and edges with three equivalent Mg(2)S6 octahedra. In the second Mg site, Mg(2) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form MgS6 octahedra that share corners with two equivalent Ga(1)S4 tetrahedra, corners with four equivalent Ga(2)S4 tetrahedra,  an edgeedge with one Mg(3)S6 octahedra, edges with two equivalent Mg(2)S6 octahedra, and edges with three equivalent Mg(1)S6 octahedra. In the third Mg site, Mg(3) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(6) atoms to form MgS6 octahedra that share corners with four equivalent Ga(1)S4 tetrahedra, corners with six equivalent Ga(3)S4 tetrahedra,  an edgeedge with one Mg(2)S6 octahedra, and edges with two equivalent Mg(1)S6 octahedra. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(1), one S(4), one S(5), and one S(6) atom to form GaS4 tetrahedra that share  a cornercorner with one Mg(1)S6 octahedra,  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Mg(3)S6 octahedra, corners with two equivalent Ga(3)S4 tetrahedra, and corners with three equivalent Ga(2)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-62°. In the second Ga site, Ga(2) is bonded to one S(2), one S(4), and two equivalent S(5) atoms to form GaS4 tetrahedra that share  a cornercorner with one Mg(1)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra,  a cornercorner with one Ga(3)S4 tetrahedra, corners with two equivalent Ga(2)S4 tetrahedra, and corners with three equivalent Ga(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. In the third Ga site, Ga(3) is bonded to one S(4), one S(6), and two equivalent S(3) atoms to form GaS4 tetrahedra that share corners with two equivalent Mg(1)S6 octahedra, corners with three equivalent Mg(3)S6 octahedra,  a cornercorner with one Ga(2)S4 tetrahedra, corners with two equivalent Ga(1)S4 tetrahedra, and  an edgeedge with one Ga(3)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. There are six inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(3), and one Ga(1) atom. In the second S site, S(2) is bonded to one Mg(1), two equivalent Mg(2), and one Ga(2) atom to form a mixture of distorted edge and corner-sharing SMg3Ga trigonal pyramids. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mg(3), and two equivalent Ga(3) atoms. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Ga(1), one Ga(2), and one Ga(3) atom. In the fifth S site, S(5) is bonded in a trigonal non-coplanar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the sixth S site, S(6) is bonded in a trigonal planar geometry to one Mg(3), one Ga(1), and one Ga(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg(GaS2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.003
_cell_length_b   13.003
_cell_length_c   6.414
_cell_angle_alpha   80.945
_cell_angle_beta   80.945
_cell_angle_gamma   120.896
_symmetry_Int_Tables_number   1
_cell_volume   881.897
_cell_formula_units_Z   6
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
  Mg  Mg0  1  0.871  0.129  0.750  1.0
  Mg  Mg1  1  0.129  0.871  0.250  1.0
  Mg  Mg2  1  0.044  0.956  0.750  1.0
  Mg  Mg3  1  0.956  0.044  0.250  1.0
  Mg  Mg4  1  0.219  0.781  0.750  1.0
  Mg  Mg5  1  0.781  0.219  0.250  1.0
  Ga  Ga6  1  0.585  0.835  0.616  1.0
  Ga  Ga7  1  0.165  0.415  0.884  1.0
  Ga  Ga8  1  0.415  0.165  0.384  1.0
  Ga  Ga9  1  0.835  0.585  0.116  1.0
  Ga  Ga10  1  0.754  0.673  0.616  1.0
  Ga  Ga11  1  0.327  0.246  0.884  1.0
  Ga  Ga12  1  0.246  0.327  0.384  1.0
  Ga  Ga13  1  0.673  0.754  0.116  1.0
  Ga  Ga14  1  0.886  0.485  0.645  1.0
  Ga  Ga15  1  0.515  0.114  0.855  1.0
  Ga  Ga16  1  0.114  0.515  0.355  1.0
  Ga  Ga17  1  0.485  0.886  0.145  1.0
  S  S18  1  0.759  0.024  0.481  1.0
  S  S19  1  0.976  0.241  0.019  1.0
  S  S20  1  0.241  0.976  0.519  1.0
  S  S21  1  0.024  0.759  0.981  1.0
  S  S22  1  0.937  0.850  0.481  1.0
  S  S23  1  0.150  0.063  0.019  1.0
  S  S24  1  0.063  0.150  0.519  1.0
  S  S25  1  0.850  0.937  0.981  1.0
  S  S26  1  0.089  0.656  0.495  1.0
  S  S27  1  0.344  0.911  0.005  1.0
  S  S28  1  0.911  0.344  0.505  1.0
  S  S29  1  0.656  0.089  0.995  1.0
  S  S30  1  0.747  0.511  0.498  1.0
  S  S31  1  0.489  0.253  0.002  1.0
  S  S32  1  0.253  0.489  0.502  1.0
  S  S33  1  0.511  0.747  0.998  1.0
  S  S34  1  0.596  0.677  0.499  1.0
  S  S35  1  0.323  0.404  0.001  1.0
  S  S36  1  0.404  0.323  0.501  1.0
  S  S37  1  0.677  0.596  0.999  1.0
  S  S38  1  0.419  0.815  0.510  1.0
  S  S39  1  0.185  0.581  0.990  1.0
  S  S40  1  0.581  0.185  0.490  1.0
  S  S41  1  0.815  0.419  0.010  1.0
[/CIF]
.
The compound described by MgGa2S4 crystallizes in the monoclinic C2/c space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form MgS6 octahedra that share corners with two equivalent Ga(1)S4 tetrahedra, corners with two equivalent Ga(2)S4 tetrahedra, corners with four equivalent Ga(3)S4 tetrahedra, edges with two equivalent Mg(3)S6 octahedra, and edges with three equivalent Mg(2)S6 octahedra. In the second Mg site, Mg(2) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form MgS6 octahedra that share corners with two equivalent Ga(1)S4 tetrahedra, corners with four equivalent Ga(2)S4 tetrahedra,  an edgeedge with one Mg(3)S6 octahedra, edges with two equivalent Mg(2)S6 octahedra, and edges with three equivalent Mg(1)S6 octahedra. In the third Mg site, Mg(3) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(6) atoms to form MgS6 octahedra that share corners with four equivalent Ga(1)S4 tetrahedra, corners with six equivalent Ga(3)S4 tetrahedra,  an edgeedge with one Mg(2)S6 octahedra, and edges with two equivalent Mg(1)S6 octahedra. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one S(1), one S(4), one S(5), and one S(6) atom to form GaS4 tetrahedra that share  a cornercorner with one Mg(1)S6 octahedra,  a cornercorner with one Mg(2)S6 octahedra, corners with two equivalent Mg(3)S6 octahedra, corners with two equivalent Ga(3)S4 tetrahedra, and corners with three equivalent Ga(2)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-62°. In the second Ga site, Ga(2) is bonded to one S(2), one S(4), and two equivalent S(5) atoms to form GaS4 tetrahedra that share  a cornercorner with one Mg(1)S6 octahedra, corners with two equivalent Mg(2)S6 octahedra,  a cornercorner with one Ga(3)S4 tetrahedra, corners with two equivalent Ga(2)S4 tetrahedra, and corners with three equivalent Ga(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. In the third Ga site, Ga(3) is bonded to one S(4), one S(6), and two equivalent S(3) atoms to form GaS4 tetrahedra that share corners with two equivalent Mg(1)S6 octahedra, corners with three equivalent Mg(3)S6 octahedra,  a cornercorner with one Ga(2)S4 tetrahedra, corners with two equivalent Ga(1)S4 tetrahedra, and  an edgeedge with one Ga(3)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. There are six inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mg(2), one Mg(3), and one Ga(1) atom. In the second S site, S(2) is bonded to one Mg(1), two equivalent Mg(2), and one Ga(2) atom to form a mixture of distorted edge and corner-sharing SMg3Ga trigonal pyramids. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mg(3), and two equivalent Ga(3) atoms. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Ga(1), one Ga(2), and one Ga(3) atom. In the fifth S site, S(5) is bonded in a trigonal non-coplanar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the sixth S site, S(6) is bonded in a trigonal planar geometry to one Mg(3), one Ga(1), and one Ga(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg(GaS2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.003
_cell_length_b   13.003
_cell_length_c   6.414
_cell_angle_alpha   80.945
_cell_angle_beta   80.945
_cell_angle_gamma   120.896
_symmetry_Int_Tables_number   1
_cell_volume   881.897
_cell_formula_units_Z   6
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
  Mg  Mg0  1  0.871  0.129  0.750  1.0
  Mg  Mg1  1  0.129  0.871  0.250  1.0
  Mg  Mg2  1  0.044  0.956  0.750  1.0
  Mg  Mg3  1  0.956  0.044  0.250  1.0
  Mg  Mg4  1  0.219  0.781  0.750  1.0
  Mg  Mg5  1  0.781  0.219  0.250  1.0
  Ga  Ga6  1  0.585  0.835  0.616  1.0
  Ga  Ga7  1  0.165  0.415  0.884  1.0
  Ga  Ga8  1  0.415  0.165  0.384  1.0
  Ga  Ga9  1  0.835  0.585  0.116  1.0
  Ga  Ga10  1  0.754  0.673  0.616  1.0
  Ga  Ga11  1  0.327  0.246  0.884  1.0
  Ga  Ga12  1  0.246  0.327  0.384  1.0
  Ga  Ga13  1  0.673  0.754  0.116  1.0
  Ga  Ga14  1  0.886  0.485  0.645  1.0
  Ga  Ga15  1  0.515  0.114  0.855  1.0
  Ga  Ga16  1  0.114  0.515  0.355  1.0
  Ga  Ga17  1  0.485  0.886  0.145  1.0
  S  S18  1  0.759  0.024  0.481  1.0
  S  S19  1  0.976  0.241  0.019  1.0
  S  S20  1  0.241  0.976  0.519  1.0
  S  S21  1  0.024  0.759  0.981  1.0
  S  S22  1  0.937  0.850  0.481  1.0
  S  S23  1  0.150  0.063  0.019  1.0
  S  S24  1  0.063  0.150  0.519  1.0
  S  S25  1  0.850  0.937  0.981  1.0
  S  S26  1  0.089  0.656  0.495  1.0
  S  S27  1  0.344  0.911  0.005  1.0
  S  S28  1  0.911  0.344  0.505  1.0
  S  S29  1  0.656  0.089  0.995  1.0
  S  S30  1  0.747  0.511  0.498  1.0
  S  S31  1  0.489  0.253  0.002  1.0
  S  S32  1  0.253  0.489  0.502  1.0
  S  S33  1  0.511  0.747  0.998  1.0
  S  S34  1  0.596  0.677  0.499  1.0
  S  S35  1  0.323  0.404  0.001  1.0
  S  S36  1  0.404  0.323  0.501  1.0
  S  S37  1  0.677  0.596  0.999  1.0
  S  S38  1  0.419  0.815  0.510  1.0
  S  S39  1  0.185  0.581  0.990  1.0
  S  S40  1  0.581  0.185  0.490  1.0
  S  S41  1  0.815  0.419  0.010  1.0
[/CIF]
.