The structure described by MgCo2(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with six equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(6) atom. In the second Co site, Co(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), one O(7), and one O(8) atom. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Co(1), one Ni(1), one Ni(2), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the second O site, O(2) is bonded to one Mg(1), one Co(1), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the third O site, O(3) is bonded to one Mg(1), one Co(2), one Ni(2), one Ni(3), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Co(2), one Ni(1), one Ni(3), and one Ni(4) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Ni(1), one Ni(3), and one Ni(4) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Co(1), one Ni(2), one Ni(3), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Co(2), one Ni(1), one Ni(2), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the eighth O site, O(8) is bonded to one Mg(1), one Co(2), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCo2(NiO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.856
_cell_length_b   5.840
_cell_length_c   6.166
_cell_angle_alpha   61.692
_cell_angle_beta   61.589
_cell_angle_gamma   59.991
_symmetry_Int_Tables_number   1
_cell_volume   152.711
_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  0.021  0.996  0.500  1.0
  Co  Co1  1  0.124  0.164  0.037  1.0
  Co  Co2  1  0.820  0.846  0.963  1.0
  Ni  Ni3  1  0.502  0.998  0.501  1.0
  Ni  Ni4  1  0.488  0.502  1.000  1.0
  Ni  Ni5  1  0.009  0.498  0.496  1.0
  Ni  Ni6  1  0.503  0.500  0.504  1.0
  O  O7  1  0.757  0.246  0.253  1.0
  O  O8  1  0.251  0.245  0.248  1.0
  O  O9  1  0.758  0.244  0.748  1.0
  O  O10  1  0.740  0.731  0.304  1.0
  O  O11  1  0.275  0.266  0.696  1.0
  O  O12  1  0.251  0.756  0.250  1.0
  O  O13  1  0.244  0.753  0.753  1.0
  O  O14  1  0.757  0.754  0.748  1.0
[/CIF]
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The structure described by MgCo2(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with six equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(5), and one O(6) atom. In the second Co site, Co(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), one O(7), and one O(8) atom. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Co(1), one Ni(1), one Ni(2), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the second O site, O(2) is bonded to one Mg(1), one Co(1), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the third O site, O(3) is bonded to one Mg(1), one Co(2), one Ni(2), one Ni(3), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Co(2), one Ni(1), one Ni(3), and one Ni(4) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Ni(1), one Ni(3), and one Ni(4) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Co(1), one Ni(2), one Ni(3), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the seventh O site, O(7) is bonded to one Mg(1), one Co(2), one Ni(1), one Ni(2), and one Ni(4) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. In the eighth O site, O(8) is bonded to one Mg(1), one Co(2), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of edge and corner-sharing OMgCoNi3 square pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCo2(NiO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.856
_cell_length_b   5.840
_cell_length_c   6.166
_cell_angle_alpha   61.692
_cell_angle_beta   61.589
_cell_angle_gamma   59.991
_symmetry_Int_Tables_number   1
_cell_volume   152.711
_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  0.021  0.996  0.500  1.0
  Co  Co1  1  0.124  0.164  0.037  1.0
  Co  Co2  1  0.820  0.846  0.963  1.0
  Ni  Ni3  1  0.502  0.998  0.501  1.0
  Ni  Ni4  1  0.488  0.502  1.000  1.0
  Ni  Ni5  1  0.009  0.498  0.496  1.0
  Ni  Ni6  1  0.503  0.500  0.504  1.0
  O  O7  1  0.757  0.246  0.253  1.0
  O  O8  1  0.251  0.245  0.248  1.0
  O  O9  1  0.758  0.244  0.748  1.0
  O  O10  1  0.740  0.731  0.304  1.0
  O  O11  1  0.275  0.266  0.696  1.0
  O  O12  1  0.251  0.756  0.250  1.0
  O  O13  1  0.244  0.753  0.753  1.0
  O  O14  1  0.757  0.754  0.748  1.0
[/CIF]
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