The compound described by K2Mg(FeO2)2 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) 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 Mg(1)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 trigonal pyramid, and edges with two equivalent Fe(2)O4 trigonal pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with three equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 trigonal pyramid. 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 trigonal pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 trigonal pyramids,  an edgeedge with one Fe(1)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 two equivalent K(2), two equivalent Mg(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent 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 one K(2), two equivalent K(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF card [CIF]
data_K2Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.874
_cell_length_b   5.950
_cell_length_c   8.719
_cell_angle_alpha   59.258
_cell_angle_beta   120.833
_cell_angle_gamma   147.177
_symmetry_Int_Tables_number   1
_cell_volume   139.707
_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  0.158  0.834  0.621  1.0
  K  K1  1  0.847  0.184  0.379  1.0
  Mg  Mg2  1  0.687  0.312  0.960  1.0
  Fe  Fe3  1  0.024  0.974  0.179  1.0
  Fe  Fe4  1  0.927  0.014  0.821  1.0
  O  O5  1  0.161  0.835  0.068  1.0
  O  O6  1  0.496  0.505  0.713  1.0
  O  O7  1  0.565  0.433  0.323  1.0
  O  O8  1  0.856  0.180  0.914  1.0
[/CIF]
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The compound described by K2Mg(FeO2)2 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) 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 Mg(1)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra,  a cornercorner with one Fe(2)O4 trigonal pyramid, and edges with two equivalent Fe(2)O4 trigonal pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with three equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Fe(2)O4 trigonal pyramid. 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 trigonal pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 trigonal pyramids,  an edgeedge with one Fe(1)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 two equivalent K(2), two equivalent Mg(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent 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 one K(2), two equivalent K(1), and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF card [CIF]
data_K2Mg(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.874
_cell_length_b   5.950
_cell_length_c   8.719
_cell_angle_alpha   59.258
_cell_angle_beta   120.833
_cell_angle_gamma   147.177
_symmetry_Int_Tables_number   1
_cell_volume   139.707
_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  0.158  0.834  0.621  1.0
  K  K1  1  0.847  0.184  0.379  1.0
  Mg  Mg2  1  0.687  0.312  0.960  1.0
  Fe  Fe3  1  0.024  0.974  0.179  1.0
  Fe  Fe4  1  0.927  0.014  0.821  1.0
  O  O5  1  0.161  0.835  0.068  1.0
  O  O6  1  0.496  0.505  0.713  1.0
  O  O7  1  0.565  0.433  0.323  1.0
  O  O8  1  0.856  0.180  0.914  1.0
[/CIF]
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