The material structure described by Mg(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Ni site, Ni(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the third Ni site, Ni(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the fourth Ni site, Ni(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ni(1) and two equivalent Ni(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ni(4) and two equivalent Ni(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ni(2) and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Ni(4), and two equivalent Ni(1) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Mg(1), one Ni(1), and two equivalent Ni(4) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Mg(1), one Ni(2), and two equivalent Ni(3) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. is represented by the CIF file [CIF]
data_Mg(NiO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.969
_cell_length_b   6.669
_cell_length_c   6.664
_cell_angle_alpha   87.320
_cell_angle_beta   77.104
_cell_angle_gamma   77.169
_symmetry_Int_Tables_number   1
_cell_volume   125.430
_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  0.499  1.000  0.999  1.0
  Ni  Ni1  1  0.651  0.178  0.526  1.0
  Ni  Ni2  1  0.176  0.475  0.179  1.0
  Ni  Ni3  1  0.828  0.526  0.823  1.0
  Ni  Ni4  1  0.353  0.822  0.477  1.0
  O  O5  1  0.830  0.721  0.623  1.0
  O  O6  1  0.452  0.382  0.719  1.0
  O  O7  1  0.552  0.619  0.283  1.0
  O  O8  1  0.174  0.279  0.379  1.0
  O  O9  1  0.141  0.040  0.683  1.0
  O  O10  1  0.824  0.318  0.039  1.0
  O  O11  1  0.863  0.960  0.320  1.0
  O  O12  1  0.181  0.682  0.963  1.0
[/CIF]
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The material structure described by Mg(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a body-centered cubic geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the second Ni site, Ni(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the third Ni site, Ni(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. In the fourth Ni site, Ni(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ni(1) and two equivalent Ni(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ni(4) and two equivalent Ni(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ni(2) and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), one Ni(4), and two equivalent Ni(1) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Mg(1), one Ni(1), and two equivalent Ni(4) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Mg(1), one Ni(2), and two equivalent Ni(3) atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. is represented by the CIF file [CIF]
data_Mg(NiO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.969
_cell_length_b   6.669
_cell_length_c   6.664
_cell_angle_alpha   87.320
_cell_angle_beta   77.104
_cell_angle_gamma   77.169
_symmetry_Int_Tables_number   1
_cell_volume   125.430
_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  0.499  1.000  0.999  1.0
  Ni  Ni1  1  0.651  0.178  0.526  1.0
  Ni  Ni2  1  0.176  0.475  0.179  1.0
  Ni  Ni3  1  0.828  0.526  0.823  1.0
  Ni  Ni4  1  0.353  0.822  0.477  1.0
  O  O5  1  0.830  0.721  0.623  1.0
  O  O6  1  0.452  0.382  0.719  1.0
  O  O7  1  0.552  0.619  0.283  1.0
  O  O8  1  0.174  0.279  0.379  1.0
  O  O9  1  0.141  0.040  0.683  1.0
  O  O10  1  0.824  0.318  0.039  1.0
  O  O11  1  0.863  0.960  0.320  1.0
  O  O12  1  0.181  0.682  0.963  1.0
[/CIF]
.