The compound described by Na3Ni2O5 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-19°. In the second Na site, Na(2) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-20°. In the third Na site, Na(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form NaO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth Na site, Na(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-20°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(3)O6 octahedra, corners with three equivalent Na(2)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the second Ni site, Ni(2) is bonded to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with three equivalent Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-17°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), and two equivalent Ni(1) atoms to form ONa4Ni2 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra,  a cornercorner with one O(5)Na4Ni2 octahedra, corners with two equivalent O(4)Na3Ni3 octahedra, corners with two equivalent O(1)Na4Ni2 octahedra,  an edgeedge with one O(1)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(4)Na3Ni3 octahedra, edges with three equivalent O(5)Na4Ni2 octahedra, and edges with four equivalent O(2)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second O site, O(2) is bonded to one Na(3), one Na(4), two equivalent Na(1), one Ni(1), and one Ni(2) atom to form distorted ONa4Ni2 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra,  a cornercorner with one O(4)Na3Ni3 octahedra, corners with two equivalent O(2)Na4Ni2 octahedra, corners with two equivalent O(5)Na4Ni2 octahedra,  an edgeedge with one O(2)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(5)Na4Ni2 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with four equivalent O(1)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one Ni(1), and two equivalent Ni(2) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(1)Na4Ni2 octahedra,  a cornercorner with one O(2)Na4Ni2 octahedra, corners with two equivalent O(4)Na3Ni3 octahedra, corners with two equivalent O(5)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(1)Na4Ni2 octahedra, edges with two equivalent O(2)Na4Ni2 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with three equivalent O(5)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-11°. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Ni(1), and two equivalent Ni(2) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(4)Na3Ni3 octahedra,  a cornercorner with one O(2)Na4Ni2 octahedra, corners with two equivalent O(3)Na3Ni3 octahedra, corners with two equivalent O(1)Na4Ni2 octahedra,  an edgeedge with one O(4)Na3Ni3 octahedra, edges with two equivalent O(1)Na4Ni2 octahedra, edges with three equivalent O(3)Na3Ni3 octahedra, edges with three equivalent O(2)Na4Ni2 octahedra, and edges with three equivalent O(5)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the fifth O site, O(5) is bonded to one Na(1), one Na(4), two equivalent Na(2), one Ni(1), and one Ni(2) atom to form distorted ONa4Ni2 octahedra that share  a cornercorner with one O(1)Na4Ni2 octahedra,  a cornercorner with one O(5)Na4Ni2 octahedra, corners with two equivalent O(3)Na3Ni3 octahedra, corners with two equivalent O(2)Na4Ni2 octahedra,  an edgeedge with one O(5)Na4Ni2 octahedra, edges with two equivalent O(2)Na4Ni2 octahedra, edges with three equivalent O(3)Na3Ni3 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with three equivalent O(1)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. is represented by the CIF card [CIF]
data_Na3Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.280
_cell_length_b   6.305
_cell_length_c   6.905
_cell_angle_alpha   107.611
_cell_angle_beta   96.482
_cell_angle_gamma   107.236
_symmetry_Int_Tables_number   1
_cell_volume   204.024
_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
  Na  Na0  1  0.620  0.712  0.201  1.0
  Na  Na1  1  0.380  0.288  0.799  1.0
  Na  Na2  1  0.205  0.903  0.389  1.0
  Na  Na3  1  0.000  0.500  0.000  1.0
  Na  Na4  1  0.000  0.000  0.000  1.0
  Na  Na5  1  0.795  0.097  0.611  1.0
  Ni  Ni6  1  0.602  0.205  0.204  1.0
  Ni  Ni7  1  0.398  0.795  0.796  1.0
  Ni  Ni8  1  0.202  0.405  0.406  1.0
  Ni  Ni9  1  0.798  0.595  0.594  1.0
  O  O10  1  0.651  0.121  0.920  1.0
  O  O11  1  0.670  0.656  0.851  1.0
  O  O12  1  0.476  0.719  0.524  1.0
  O  O13  1  0.524  0.281  0.476  1.0
  O  O14  1  0.349  0.879  0.080  1.0
  O  O15  1  0.330  0.344  0.149  1.0
  O  O16  1  0.877  0.516  0.318  1.0
  O  O17  1  0.898  0.110  0.306  1.0
  O  O18  1  0.102  0.890  0.694  1.0
  O  O19  1  0.123  0.484  0.682  1.0
[/CIF]
.
The compound described by Na3Ni2O5 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-19°. In the second Na site, Na(2) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(4)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-20°. In the third Na site, Na(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form NaO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-13°. In the fourth Na site, Na(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-20°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Na(3)O6 octahedra, corners with three equivalent Na(2)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the second Ni site, Ni(2) is bonded to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with three equivalent Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-17°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), and two equivalent Ni(1) atoms to form ONa4Ni2 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra,  a cornercorner with one O(5)Na4Ni2 octahedra, corners with two equivalent O(4)Na3Ni3 octahedra, corners with two equivalent O(1)Na4Ni2 octahedra,  an edgeedge with one O(1)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(4)Na3Ni3 octahedra, edges with three equivalent O(5)Na4Ni2 octahedra, and edges with four equivalent O(2)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second O site, O(2) is bonded to one Na(3), one Na(4), two equivalent Na(1), one Ni(1), and one Ni(2) atom to form distorted ONa4Ni2 octahedra that share  a cornercorner with one O(3)Na3Ni3 octahedra,  a cornercorner with one O(4)Na3Ni3 octahedra, corners with two equivalent O(2)Na4Ni2 octahedra, corners with two equivalent O(5)Na4Ni2 octahedra,  an edgeedge with one O(2)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(5)Na4Ni2 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with four equivalent O(1)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one Ni(1), and two equivalent Ni(2) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(1)Na4Ni2 octahedra,  a cornercorner with one O(2)Na4Ni2 octahedra, corners with two equivalent O(4)Na3Ni3 octahedra, corners with two equivalent O(5)Na4Ni2 octahedra, edges with two equivalent O(3)Na3Ni3 octahedra, edges with two equivalent O(1)Na4Ni2 octahedra, edges with two equivalent O(2)Na4Ni2 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with three equivalent O(5)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-11°. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Ni(1), and two equivalent Ni(2) atoms to form ONa3Ni3 octahedra that share  a cornercorner with one O(4)Na3Ni3 octahedra,  a cornercorner with one O(2)Na4Ni2 octahedra, corners with two equivalent O(3)Na3Ni3 octahedra, corners with two equivalent O(1)Na4Ni2 octahedra,  an edgeedge with one O(4)Na3Ni3 octahedra, edges with two equivalent O(1)Na4Ni2 octahedra, edges with three equivalent O(3)Na3Ni3 octahedra, edges with three equivalent O(2)Na4Ni2 octahedra, and edges with three equivalent O(5)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the fifth O site, O(5) is bonded to one Na(1), one Na(4), two equivalent Na(2), one Ni(1), and one Ni(2) atom to form distorted ONa4Ni2 octahedra that share  a cornercorner with one O(1)Na4Ni2 octahedra,  a cornercorner with one O(5)Na4Ni2 octahedra, corners with two equivalent O(3)Na3Ni3 octahedra, corners with two equivalent O(2)Na4Ni2 octahedra,  an edgeedge with one O(5)Na4Ni2 octahedra, edges with two equivalent O(2)Na4Ni2 octahedra, edges with three equivalent O(3)Na3Ni3 octahedra, edges with three equivalent O(4)Na3Ni3 octahedra, and edges with three equivalent O(1)Na4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. is represented by the CIF card [CIF]
data_Na3Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.280
_cell_length_b   6.305
_cell_length_c   6.905
_cell_angle_alpha   107.611
_cell_angle_beta   96.482
_cell_angle_gamma   107.236
_symmetry_Int_Tables_number   1
_cell_volume   204.024
_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
  Na  Na0  1  0.620  0.712  0.201  1.0
  Na  Na1  1  0.380  0.288  0.799  1.0
  Na  Na2  1  0.205  0.903  0.389  1.0
  Na  Na3  1  0.000  0.500  0.000  1.0
  Na  Na4  1  0.000  0.000  0.000  1.0
  Na  Na5  1  0.795  0.097  0.611  1.0
  Ni  Ni6  1  0.602  0.205  0.204  1.0
  Ni  Ni7  1  0.398  0.795  0.796  1.0
  Ni  Ni8  1  0.202  0.405  0.406  1.0
  Ni  Ni9  1  0.798  0.595  0.594  1.0
  O  O10  1  0.651  0.121  0.920  1.0
  O  O11  1  0.670  0.656  0.851  1.0
  O  O12  1  0.476  0.719  0.524  1.0
  O  O13  1  0.524  0.281  0.476  1.0
  O  O14  1  0.349  0.879  0.080  1.0
  O  O15  1  0.330  0.344  0.149  1.0
  O  O16  1  0.877  0.516  0.318  1.0
  O  O17  1  0.898  0.110  0.306  1.0
  O  O18  1  0.102  0.890  0.694  1.0
  O  O19  1  0.123  0.484  0.682  1.0
[/CIF]
.