The material structure described by NaNi2O3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Ni(4)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-11°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with three equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with six equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with three equivalent Ni(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. In the third Ni site, Ni(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Ni(2)O6 octahedra, and edges with six equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-14°. In the fourth Ni site, Ni(4) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Ni(2)O6 octahedra, and edges with six equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-13°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Ni(1), one Ni(4), and two equivalent Ni(2) atoms to form a mixture of distorted corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to two equivalent Na(2), one Ni(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the third O site, O(3) is bonded to two equivalent Na(1), one Ni(1), one Ni(4), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Ni(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaNi2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.225
_cell_length_b   10.093
_cell_length_c   5.225
_cell_angle_alpha   94.461
_cell_angle_beta   118.928
_cell_angle_gamma   94.467
_symmetry_Int_Tables_number   1
_cell_volume   238.308
_cell_formula_units_Z   4
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
  Na  Na0  1  0.080  0.250  0.420  1.0
  Na  Na1  1  0.580  0.750  0.920  1.0
  Na  Na2  1  0.420  0.250  0.080  1.0
  Na  Na3  1  0.920  0.750  0.580  1.0
  Ni  Ni4  1  0.993  0.999  0.993  1.0
  Ni  Ni5  1  0.507  0.501  0.507  1.0
  Ni  Ni6  1  0.334  0.000  0.664  1.0
  Ni  Ni7  1  0.835  0.500  0.166  1.0
  Ni  Ni8  1  0.166  0.500  0.835  1.0
  Ni  Ni9  1  0.664  0.000  0.334  1.0
  Ni  Ni10  1  0.250  0.750  0.250  1.0
  Ni  Ni11  1  0.750  0.250  0.750  1.0
  O  O12  1  0.419  0.125  0.419  1.0
  O  O13  1  0.902  0.617  0.902  1.0
  O  O14  1  0.081  0.375  0.081  1.0
  O  O15  1  0.598  0.883  0.598  1.0
  O  O16  1  0.020  0.107  0.719  1.0
  O  O17  1  0.520  0.603  0.218  1.0
  O  O18  1  0.719  0.107  0.020  1.0
  O  O19  1  0.218  0.603  0.520  1.0
  O  O20  1  0.480  0.393  0.781  1.0
  O  O21  1  0.980  0.896  0.282  1.0
  O  O22  1  0.781  0.393  0.480  1.0
  O  O23  1  0.282  0.897  0.980  1.0
[/CIF]
.
The material structure described by NaNi2O3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Ni(4)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-11°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with three equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-12°. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with six equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one Ni(4)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with three equivalent Ni(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-14°. In the third Ni site, Ni(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Ni(2)O6 octahedra, and edges with six equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-14°. In the fourth Ni site, Ni(4) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with four equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Ni(2)O6 octahedra, and edges with six equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-13°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Ni(1), one Ni(4), and two equivalent Ni(2) atoms to form a mixture of distorted corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to two equivalent Na(2), one Ni(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the third O site, O(3) is bonded to two equivalent Na(1), one Ni(1), one Ni(4), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Ni(1), one Ni(3), and two equivalent Ni(2) atoms to form a mixture of corner and edge-sharing ONa2Ni4 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaNi2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.225
_cell_length_b   10.093
_cell_length_c   5.225
_cell_angle_alpha   94.461
_cell_angle_beta   118.928
_cell_angle_gamma   94.467
_symmetry_Int_Tables_number   1
_cell_volume   238.308
_cell_formula_units_Z   4
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
  Na  Na0  1  0.080  0.250  0.420  1.0
  Na  Na1  1  0.580  0.750  0.920  1.0
  Na  Na2  1  0.420  0.250  0.080  1.0
  Na  Na3  1  0.920  0.750  0.580  1.0
  Ni  Ni4  1  0.993  0.999  0.993  1.0
  Ni  Ni5  1  0.507  0.501  0.507  1.0
  Ni  Ni6  1  0.334  0.000  0.664  1.0
  Ni  Ni7  1  0.835  0.500  0.166  1.0
  Ni  Ni8  1  0.166  0.500  0.835  1.0
  Ni  Ni9  1  0.664  0.000  0.334  1.0
  Ni  Ni10  1  0.250  0.750  0.250  1.0
  Ni  Ni11  1  0.750  0.250  0.750  1.0
  O  O12  1  0.419  0.125  0.419  1.0
  O  O13  1  0.902  0.617  0.902  1.0
  O  O14  1  0.081  0.375  0.081  1.0
  O  O15  1  0.598  0.883  0.598  1.0
  O  O16  1  0.020  0.107  0.719  1.0
  O  O17  1  0.520  0.603  0.218  1.0
  O  O18  1  0.719  0.107  0.020  1.0
  O  O19  1  0.218  0.603  0.520  1.0
  O  O20  1  0.480  0.393  0.781  1.0
  O  O21  1  0.980  0.896  0.282  1.0
  O  O22  1  0.781  0.393  0.480  1.0
  O  O23  1  0.282  0.897  0.980  1.0
[/CIF]
.