The material structure described by Mg(NiO2)2 is Spinel structured and crystallizes in the monoclinic C2/m space group. 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 three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(3)O6 octahedra, and corners with six equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-67°. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, 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. In the third Ni site, Ni(3) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing OMgNi3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Ni(1), and two equivalent Ni(2) atoms to form a mixture of distorted corner and edge-sharing OMgNi3 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ni(3), and two equivalent Ni(2) atoms. is represented by the CIF card [CIF]
data_Mg(NiO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.804
_cell_length_b   5.804
_cell_length_c   5.823
_cell_angle_alpha   59.743
_cell_angle_beta   59.743
_cell_angle_gamma   59.953
_symmetry_Int_Tables_number   1
_cell_volume   138.103
_cell_formula_units_Z   2
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  0.879  0.879  0.367  1.0
  Mg  Mg1  1  0.121  0.121  0.633  1.0
  Ni  Ni2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.000  0.500  0.000  1.0
  Ni  Ni4  1  0.500  0.000  0.000  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.704  0.261  0.755  1.0
  O  O7  1  0.261  0.704  0.755  1.0
  O  O8  1  0.243  0.243  0.803  1.0
  O  O9  1  0.727  0.727  0.775  1.0
  O  O10  1  0.757  0.757  0.197  1.0
  O  O11  1  0.739  0.296  0.245  1.0
  O  O12  1  0.273  0.273  0.225  1.0
  O  O13  1  0.296  0.739  0.245  1.0
[/CIF]
.
The material structure described by Mg(NiO2)2 is Spinel structured and crystallizes in the monoclinic C2/m space group. 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 three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(3)O6 octahedra, and corners with six equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-67°. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, 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. In the third Ni site, Ni(3) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Mg(1)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing OMgNi3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Ni(1), and two equivalent Ni(2) atoms to form a mixture of distorted corner and edge-sharing OMgNi3 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ni(3), and two equivalent Ni(2) atoms. is represented by the CIF card [CIF]
data_Mg(NiO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.804
_cell_length_b   5.804
_cell_length_c   5.823
_cell_angle_alpha   59.743
_cell_angle_beta   59.743
_cell_angle_gamma   59.953
_symmetry_Int_Tables_number   1
_cell_volume   138.103
_cell_formula_units_Z   2
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  0.879  0.879  0.367  1.0
  Mg  Mg1  1  0.121  0.121  0.633  1.0
  Ni  Ni2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.000  0.500  0.000  1.0
  Ni  Ni4  1  0.500  0.000  0.000  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.704  0.261  0.755  1.0
  O  O7  1  0.261  0.704  0.755  1.0
  O  O8  1  0.243  0.243  0.803  1.0
  O  O9  1  0.727  0.727  0.775  1.0
  O  O10  1  0.757  0.757  0.197  1.0
  O  O11  1  0.739  0.296  0.245  1.0
  O  O12  1  0.273  0.273  0.225  1.0
  O  O13  1  0.296  0.739  0.245  1.0
[/CIF]
.