The compound described by MgFe4(AsS)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 8-coordinate geometry to one Fe(1), one Fe(3), one As(1), one As(3), one S(1), one S(2), one S(3), and one S(4) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 7-coordinate geometry to one Mg(1), one As(1), one As(3), one As(4), one S(1), one S(2), and one S(3) atom. In the second Fe site, Fe(2) is bonded to one As(2), one As(3), one As(4), one S(1), one S(2), and one S(4) atom to form distorted FeAs3S3 octahedra that share  a cornercorner with one As(2)Fe3S tetrahedra,  a cornercorner with one As(4)Fe3S tetrahedra, and edges with two equivalent Fe(4)As3S3 octahedra. In the third Fe site, Fe(3) is bonded in a 7-coordinate geometry to one Mg(1), one As(1), one As(2), one As(3), one S(1), one S(3), and one S(4) atom. In the fourth Fe site, Fe(4) is bonded to one As(1), one As(2), one As(4), one S(2), one S(3), and one S(4) atom to form distorted FeAs3S3 octahedra that share  a cornercorner with one As(2)Fe3S tetrahedra,  a cornercorner with one As(4)Fe3S tetrahedra, and edges with two equivalent Fe(2)As3S3 octahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second As site, As(2) is bonded to one Fe(2), one Fe(3), one Fe(4), and one S(4) atom to form AsFe3S tetrahedra that share  a cornercorner with one Fe(2)As3S3 octahedra,  a cornercorner with one Fe(4)As3S3 octahedra, and  an edgeedge with one As(4)Fe3S tetrahedra. The corner-sharing octahedral tilt angles range from 69-72°. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the fourth As site, As(4) is bonded to one Fe(1), one Fe(2), one Fe(4), and one S(2) atom to form AsFe3S tetrahedra that share  a cornercorner with one Fe(2)As3S3 octahedra,  a cornercorner with one Fe(4)As3S3 octahedra, and  an edgeedge with one As(2)Fe3S tetrahedra. The corner-sharing octahedral tilt angles range from 68-71°. 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 Fe(1), one Fe(2), and one Fe(3) atom. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Fe(4), and one As(4) atom. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), one Fe(4), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(AsS)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.712
_cell_length_b   6.092
_cell_length_c   6.023
_cell_angle_alpha   109.385
_cell_angle_beta   91.187
_cell_angle_gamma   88.943
_symmetry_Int_Tables_number   1
_cell_volume   197.648
_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  0.484  0.500  0.495  1.0
  Fe  Fe1  1  0.490  0.735  0.225  1.0
  Fe  Fe2  1  0.992  0.270  0.270  1.0
  Fe  Fe3  1  0.496  0.268  0.770  1.0
  Fe  Fe4  1  0.994  0.734  0.727  1.0
  As  As5  1  0.655  0.900  0.628  1.0
  As  As6  1  0.134  0.141  0.868  1.0
  As  As7  1  0.328  0.099  0.370  1.0
  As  As8  1  0.851  0.864  0.126  1.0
  S  S9  1  0.648  0.347  0.126  1.0
  S  S10  1  0.116  0.644  0.335  1.0
  S  S11  1  0.339  0.658  0.870  1.0
  S  S12  1  0.866  0.360  0.659  1.0
[/CIF]
.
The compound described by MgFe4(AsS)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 8-coordinate geometry to one Fe(1), one Fe(3), one As(1), one As(3), one S(1), one S(2), one S(3), and one S(4) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 7-coordinate geometry to one Mg(1), one As(1), one As(3), one As(4), one S(1), one S(2), and one S(3) atom. In the second Fe site, Fe(2) is bonded to one As(2), one As(3), one As(4), one S(1), one S(2), and one S(4) atom to form distorted FeAs3S3 octahedra that share  a cornercorner with one As(2)Fe3S tetrahedra,  a cornercorner with one As(4)Fe3S tetrahedra, and edges with two equivalent Fe(4)As3S3 octahedra. In the third Fe site, Fe(3) is bonded in a 7-coordinate geometry to one Mg(1), one As(1), one As(2), one As(3), one S(1), one S(3), and one S(4) atom. In the fourth Fe site, Fe(4) is bonded to one As(1), one As(2), one As(4), one S(2), one S(3), and one S(4) atom to form distorted FeAs3S3 octahedra that share  a cornercorner with one As(2)Fe3S tetrahedra,  a cornercorner with one As(4)Fe3S tetrahedra, and edges with two equivalent Fe(2)As3S3 octahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second As site, As(2) is bonded to one Fe(2), one Fe(3), one Fe(4), and one S(4) atom to form AsFe3S tetrahedra that share  a cornercorner with one Fe(2)As3S3 octahedra,  a cornercorner with one Fe(4)As3S3 octahedra, and  an edgeedge with one As(4)Fe3S tetrahedra. The corner-sharing octahedral tilt angles range from 69-72°. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the fourth As site, As(4) is bonded to one Fe(1), one Fe(2), one Fe(4), and one S(2) atom to form AsFe3S tetrahedra that share  a cornercorner with one Fe(2)As3S3 octahedra,  a cornercorner with one Fe(4)As3S3 octahedra, and  an edgeedge with one As(2)Fe3S tetrahedra. The corner-sharing octahedral tilt angles range from 68-71°. 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 Fe(1), one Fe(2), and one Fe(3) atom. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Fe(4), and one As(4) atom. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), one Fe(4), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(AsS)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.712
_cell_length_b   6.092
_cell_length_c   6.023
_cell_angle_alpha   109.385
_cell_angle_beta   91.187
_cell_angle_gamma   88.943
_symmetry_Int_Tables_number   1
_cell_volume   197.648
_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  0.484  0.500  0.495  1.0
  Fe  Fe1  1  0.490  0.735  0.225  1.0
  Fe  Fe2  1  0.992  0.270  0.270  1.0
  Fe  Fe3  1  0.496  0.268  0.770  1.0
  Fe  Fe4  1  0.994  0.734  0.727  1.0
  As  As5  1  0.655  0.900  0.628  1.0
  As  As6  1  0.134  0.141  0.868  1.0
  As  As7  1  0.328  0.099  0.370  1.0
  As  As8  1  0.851  0.864  0.126  1.0
  S  S9  1  0.648  0.347  0.126  1.0
  S  S10  1  0.116  0.644  0.335  1.0
  S  S11  1  0.339  0.658  0.870  1.0
  S  S12  1  0.866  0.360  0.659  1.0
[/CIF]
.