The material described by K2Mg(FeO2)2 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Mg(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)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 in a trigonal planar geometry to one O(4) and two equivalent O(3) atoms. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra and edges with two equivalent Mg(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(1), two equivalent K(2), two equivalent Mg(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one K(1), two equivalent K(2), one Mg(1), and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one Fe(1), and one Fe(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.815
_cell_length_b   7.815
_cell_length_c   7.227
_cell_angle_alpha   55.850
_cell_angle_beta   124.151
_cell_angle_gamma   154.304
_symmetry_Int_Tables_number   1
_cell_volume   156.474
_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
  K  K0  1  0.260  0.741  0.734  1.0
  K  K1  1  0.771  0.231  0.236  1.0
  Mg  Mg2  1  0.556  0.445  0.670  1.0
  Fe  Fe3  1  0.024  0.977  0.276  1.0
  Fe  Fe4  1  0.957  0.044  0.801  1.0
  O  O5  1  0.107  0.894  0.837  1.0
  O  O6  1  0.410  0.592  0.608  1.0
  O  O7  1  0.586  0.415  0.432  1.0
  O  O8  1  0.899  0.102  0.984  1.0
[/CIF]
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The material described by K2Mg(FeO2)2 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Mg(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)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 in a trigonal planar geometry to one O(4) and two equivalent O(3) atoms. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra and edges with two equivalent Mg(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(1), two equivalent K(2), two equivalent Mg(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one K(1), two equivalent K(2), one Mg(1), and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), one Fe(1), and one Fe(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.815
_cell_length_b   7.815
_cell_length_c   7.227
_cell_angle_alpha   55.850
_cell_angle_beta   124.151
_cell_angle_gamma   154.304
_symmetry_Int_Tables_number   1
_cell_volume   156.474
_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
  K  K0  1  0.260  0.741  0.734  1.0
  K  K1  1  0.771  0.231  0.236  1.0
  Mg  Mg2  1  0.556  0.445  0.670  1.0
  Fe  Fe3  1  0.024  0.977  0.276  1.0
  Fe  Fe4  1  0.957  0.044  0.801  1.0
  O  O5  1  0.107  0.894  0.837  1.0
  O  O6  1  0.410  0.592  0.608  1.0
  O  O7  1  0.586  0.415  0.432  1.0
  O  O8  1  0.899  0.102  0.984  1.0
[/CIF]
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