The compound described by Mg2Cr3AlS8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(1) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. Cr(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Al(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Al(1) is bonded to six equivalent S(2) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form distorted SMgCr3 trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgAlCr2 trigonal pyramids, and edges with three equivalent S(2)MgAlCr2 trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), two equivalent Cr(1), and one Al(1) atom to form distorted SMgAlCr2 trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgAlCr2 trigonal pyramids,  an edgeedge with one S(1)MgCr3 trigonal pyramid, and edges with two equivalent S(2)MgAlCr2 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2AlCr3S8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.225
_cell_length_b   7.225
_cell_length_c   7.225
_cell_angle_alpha   60.104
_cell_angle_beta   60.102
_cell_angle_gamma   60.105
_symmetry_Int_Tables_number   1
_cell_volume   267.279
_cell_formula_units_Z   1
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  0.875  0.875  0.875  1.0
  Mg  Mg1  1  0.125  0.125  0.125  1.0
  Al  Al2  1  0.500  0.500  0.500  1.0
  Cr  Cr3  1  0.500  0.500  0.000  1.0
  Cr  Cr4  1  0.000  0.500  0.500  1.0
  Cr  Cr5  1  0.500  1.000  0.500  1.0
  S  S6  1  0.737  0.737  0.737  1.0
  S  S7  1  0.263  0.263  0.711  1.0
  S  S8  1  0.263  0.711  0.263  1.0
  S  S9  1  0.711  0.263  0.263  1.0
  S  S10  1  0.737  0.289  0.737  1.0
  S  S11  1  0.289  0.737  0.737  1.0
  S  S12  1  0.263  0.263  0.263  1.0
  S  S13  1  0.737  0.737  0.289  1.0
[/CIF]
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The compound described by Mg2Cr3AlS8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to one S(1) and three equivalent S(2) atoms to form MgS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. Cr(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form CrS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra, edges with two equivalent Al(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Al(1) is bonded to six equivalent S(2) atoms to form AlS6 octahedra that share corners with six equivalent Mg(1)S4 tetrahedra and edges with six equivalent Cr(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1) and three equivalent Cr(1) atoms to form distorted SMgCr3 trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgAlCr2 trigonal pyramids, and edges with three equivalent S(2)MgAlCr2 trigonal pyramids. In the second S site, S(2) is bonded to one Mg(1), two equivalent Cr(1), and one Al(1) atom to form distorted SMgAlCr2 trigonal pyramids that share corners with three equivalent S(1)MgCr3 trigonal pyramids, corners with nine equivalent S(2)MgAlCr2 trigonal pyramids,  an edgeedge with one S(1)MgCr3 trigonal pyramid, and edges with two equivalent S(2)MgAlCr2 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2AlCr3S8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.225
_cell_length_b   7.225
_cell_length_c   7.225
_cell_angle_alpha   60.104
_cell_angle_beta   60.102
_cell_angle_gamma   60.105
_symmetry_Int_Tables_number   1
_cell_volume   267.279
_cell_formula_units_Z   1
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  0.875  0.875  0.875  1.0
  Mg  Mg1  1  0.125  0.125  0.125  1.0
  Al  Al2  1  0.500  0.500  0.500  1.0
  Cr  Cr3  1  0.500  0.500  0.000  1.0
  Cr  Cr4  1  0.000  0.500  0.500  1.0
  Cr  Cr5  1  0.500  1.000  0.500  1.0
  S  S6  1  0.737  0.737  0.737  1.0
  S  S7  1  0.263  0.263  0.711  1.0
  S  S8  1  0.263  0.711  0.263  1.0
  S  S9  1  0.711  0.263  0.263  1.0
  S  S10  1  0.737  0.289  0.737  1.0
  S  S11  1  0.289  0.737  0.737  1.0
  S  S12  1  0.263  0.263  0.263  1.0
  S  S13  1  0.737  0.737  0.289  1.0
[/CIF]
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