data_La(NiO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.29
_cell_length_b   6.29
_cell_length_c   6.29
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   La(NiO2)2
_chemical_formula_sum   'La2 Ni4 O8'
_cell_volume   176.26
_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
  La  La0  1  0.0  0.0  0.0  1.0
  La  La1  1  0.23  0.23  0.23  1.0
  Ni  Ni2  1  0.34  0.34  0.56  1.0
  Ni  Ni3  1  0.34  0.56  0.34  1.0
  Ni  Ni4  1  0.56  0.34  0.34  1.0
  Ni  Ni5  1  0.56  0.56  0.56  1.0
  O  O6  1  0.51  0.51  0.51  1.0
  O  O7  1  0.51  0.39  0.39  1.0
  O  O8  1  0.39  0.51  0.39  1.0
  O  O9  1  0.73  0.73  0.62  1.0
  O  O10  1  0.39  0.39  0.51  1.0
  O  O11  1  0.73  0.62  0.73  1.0
  O  O12  1  0.62  0.62  0.62  1.0
  O  O13  1  0.62  0.73  0.73  1.0

data_La(NiO2)2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.29
_cell_length_b   6.29
_cell_length_c   15.42
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   La(NiO2)2
_chemical_formula_sum   'La6 Ni12 O24'
_cell_volume   528.77
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  La  La0  3  0.0  0.0  0.0  1.0
  La  La1  3  0.0  0.0  0.77  1.0
  Ni  Ni2  9  0.08  0.15  0.59  1.0
  Ni  Ni3  3  0.0  0.0  0.44  1.0
  O  O4  9  0.04  0.08  0.57  1.0
  O  O5  9  0.08  0.04  0.31  1.0
  O  O6  3  0.0  0.0  0.38  1.0
  O  O7  3  0.0  0.0  0.49  1.0

La La Ni Ni Ni Ni O O O O O O O O
LaNi2O4 crystallizes in the trigonal R3m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a distorted hexagonal planar geometry to one La(2), three equivalent Ni(1), and three equivalent O(3) atoms. The La(1)-La(2) bond length is 3.47 Å. All La(1)-Ni(1) bond lengths are 3.07 Å. All La(1)-O(3) bond lengths are 3.24 Å. In the second La site, La(2) is bonded in a 10-coordinate geometry to one La(1), three equivalent Ni(2), and six equivalent Ni(1) atoms. All La(2)-Ni(2) bond lengths are 3.63 Å. There are three shorter (3.00 Å) and three longer (3.60 Å) La(2)-Ni(1) bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a single-bond geometry to one La(1), two equivalent La(2), and one O(2) atom. The Ni(1)-O(2) bond length is 0.49 Å. In the second Ni site, Ni(2) is bonded in a linear geometry to three equivalent La(2), one O(1), and one O(4) atom. The Ni(2)-O(1) bond length is 0.84 Å. The Ni(2)-O(4) bond length is 0.84 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Ni(2) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Ni(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), one O(4), and two equivalent O(3) atoms. The O(3)-O(4) bond length is 1.26 Å. Both O(3)-O(3) bond lengths are 0.73 Å. In the fourth O site, O(4) is bonded in a single-bond geometry to one Ni(2) and three equivalent O(3) atoms.