The structure described by BaSrMg(FeO2)4 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. Sr(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Mg(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form MgO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and edges with two equivalent Fe(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), and two equivalent O(3) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form distorted FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Sr(1), one Mg(1), and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(1), one Sr(1), one Mg(1), and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Sr(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Sr(1), one Mg(1), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_BaSrMg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.729
_cell_length_b   5.737
_cell_length_c   8.338
_cell_angle_alpha   83.966
_cell_angle_beta   93.017
_cell_angle_gamma   120.044
_symmetry_Int_Tables_number   1
_cell_volume   235.937
_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
  Ba  Ba0  1  0.000  0.983  0.953  1.0
  Sr  Sr1  1  0.000  0.935  0.461  1.0
  Mg  Mg2  1  0.000  0.377  0.589  1.0
  Fe  Fe3  1  0.667  0.324  0.230  1.0
  Fe  Fe4  1  0.620  0.350  0.780  1.0
  Fe  Fe5  1  0.380  0.730  0.780  1.0
  Fe  Fe6  1  0.333  0.656  0.230  1.0
  O  O7  1  0.299  0.347  0.691  1.0
  O  O8  1  0.701  0.049  0.691  1.0
  O  O9  1  1.000  0.663  0.693  1.0
  O  O10  1  0.648  0.630  0.288  1.0
  O  O11  1  0.000  0.374  0.349  1.0
  O  O12  1  0.352  0.983  0.288  1.0
  O  O13  1  0.310  0.639  0.011  1.0
  O  O14  1  0.690  0.329  0.011  1.0
[/CIF]
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The structure described by BaSrMg(FeO2)4 crystallizes in the monoclinic Cm space group. Ba(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. Sr(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Mg(1) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form MgO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, and edges with two equivalent Fe(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), and two equivalent O(3) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 tetrahedra, and corners with three equivalent Fe(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form distorted FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Fe(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Sr(1), one Mg(1), and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ba(1), one Sr(1), one Mg(1), and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Sr(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a distorted tetrahedral geometry to one Sr(1), one Mg(1), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_BaSrMg(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.729
_cell_length_b   5.737
_cell_length_c   8.338
_cell_angle_alpha   83.966
_cell_angle_beta   93.017
_cell_angle_gamma   120.044
_symmetry_Int_Tables_number   1
_cell_volume   235.937
_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
  Ba  Ba0  1  0.000  0.983  0.953  1.0
  Sr  Sr1  1  0.000  0.935  0.461  1.0
  Mg  Mg2  1  0.000  0.377  0.589  1.0
  Fe  Fe3  1  0.667  0.324  0.230  1.0
  Fe  Fe4  1  0.620  0.350  0.780  1.0
  Fe  Fe5  1  0.380  0.730  0.780  1.0
  Fe  Fe6  1  0.333  0.656  0.230  1.0
  O  O7  1  0.299  0.347  0.691  1.0
  O  O8  1  0.701  0.049  0.691  1.0
  O  O9  1  1.000  0.663  0.693  1.0
  O  O10  1  0.648  0.630  0.288  1.0
  O  O11  1  0.000  0.374  0.349  1.0
  O  O12  1  0.352  0.983  0.288  1.0
  O  O13  1  0.310  0.639  0.011  1.0
  O  O14  1  0.690  0.329  0.011  1.0
[/CIF]
.