The material described by Mg(CoO2)4 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one O(1) and three equivalent O(2) atoms to form MgO4 tetrahedra that share corners with nine equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Co(2)O4 tetrahedra, and edges with four equivalent Co(1)O6 octahedra. In the second Co site, Co(2) is bonded to one O(4) and three equivalent O(3) atoms to form corner-sharing CoO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted corner-sharing OMgCo3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded to one Co(2) and three equivalent Co(1) atoms to form distorted corner-sharing OCo4 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg(CoO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.816
_cell_length_b   5.809
_cell_length_c   5.816
_cell_angle_alpha   58.764
_cell_angle_beta   58.717
_cell_angle_gamma   58.764
_symmetry_Int_Tables_number   1
_cell_volume   134.964
_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  0.121  0.123  0.121  1.0
  Co  Co1  1  0.002  0.499  0.499  1.0
  Co  Co2  1  0.499  0.499  0.002  1.0
  Co  Co3  1  0.499  0.003  0.499  1.0
  Co  Co4  1  0.878  0.878  0.878  1.0
  O  O5  1  0.261  0.262  0.261  1.0
  O  O6  1  0.247  0.706  0.247  1.0
  O  O7  1  0.247  0.249  0.704  1.0
  O  O8  1  0.704  0.249  0.247  1.0
  O  O9  1  0.288  0.755  0.755  1.0
  O  O10  1  0.755  0.755  0.288  1.0
  O  O11  1  0.755  0.288  0.755  1.0
  O  O12  1  0.739  0.740  0.739  1.0
[/CIF]
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The material described by Mg(CoO2)4 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one O(1) and three equivalent O(2) atoms to form MgO4 tetrahedra that share corners with nine equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Co(2)O4 tetrahedra, and edges with four equivalent Co(1)O6 octahedra. In the second Co site, Co(2) is bonded to one O(4) and three equivalent O(3) atoms to form corner-sharing CoO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted corner-sharing OMgCo3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded to one Co(2) and three equivalent Co(1) atoms to form distorted corner-sharing OCo4 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg(CoO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.816
_cell_length_b   5.809
_cell_length_c   5.816
_cell_angle_alpha   58.764
_cell_angle_beta   58.717
_cell_angle_gamma   58.764
_symmetry_Int_Tables_number   1
_cell_volume   134.964
_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  0.121  0.123  0.121  1.0
  Co  Co1  1  0.002  0.499  0.499  1.0
  Co  Co2  1  0.499  0.499  0.002  1.0
  Co  Co3  1  0.499  0.003  0.499  1.0
  Co  Co4  1  0.878  0.878  0.878  1.0
  O  O5  1  0.261  0.262  0.261  1.0
  O  O6  1  0.247  0.706  0.247  1.0
  O  O7  1  0.247  0.249  0.704  1.0
  O  O8  1  0.704  0.249  0.247  1.0
  O  O9  1  0.288  0.755  0.755  1.0
  O  O10  1  0.755  0.755  0.288  1.0
  O  O11  1  0.755  0.288  0.755  1.0
  O  O12  1  0.739  0.740  0.739  1.0
[/CIF]
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