The compound described by Na4Ni7O16 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(7) atom. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(13), one O(14), one O(16), one O(5), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded to one O(1), one O(12), one O(13), one O(14), one O(16), and one O(3) atom to form NaO6 octahedra that share  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one O(1), one O(14), one O(15), one O(16), one O(2), and one O(6) atom. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(10), one O(14), one O(2), one O(5), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(16), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(1), one O(10), one O(3), one O(4), one O(6), and one O(8) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(6)O6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(11), one O(15), one O(4), one O(5), and one O(7) atom to form edge-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded to one O(11), one O(12), one O(13), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the sixth Ni site, Ni(6) is bonded to one O(12), one O(14), one O(15), one O(4), one O(8), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the seventh Ni site, Ni(7) is bonded to one O(11), one O(13), one O(15), one O(16), one O(2), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(6)O6 octahedra. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(3), one Na(4), one Ni(1), and one Ni(3) atom. In the second O site, O(2) is bonded to one Na(1), one Na(4), one Ni(1), one Ni(2), and one Ni(7) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid,  an edgeedge with one O(7)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(3), one Ni(2), and one Ni(3) atom. In the fourth O site, O(4) is bonded to one Na(1), one Ni(3), one Ni(4), and one Ni(6) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid, corners with two equivalent O(7)NaNi3 trigonal pyramids,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Ni(1), one Ni(2), and one Ni(4) atom. In the sixth O site, O(6) is bonded to one Na(1), one Na(4), one Ni(2), one Ni(3), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(4)NaNi3 trigonal pyramid,  an edgeedge with one O(7)NaNi3 trigonal pyramid, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Na(1), one Ni(2), one Ni(4), and one Ni(5) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(4)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid, and  an edgeedge with one O(6)Na2Ni3 square pyramid. In the eighth O site, O(8) is bonded to one Na(2), one Ni(3), one Ni(5), and one Ni(6) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid, and  an edgeedge with one O(4)NaNi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Na(2), one Ni(1), one Ni(6), and one Ni(7) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid, corners with two equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid, and  an edgeedge with one O(15)NaNi3 trigonal pyramid. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Ni(1), one Ni(3), and one Ni(4) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Ni(4), one Ni(5), and one Ni(7) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ni(5), and one Ni(6) atom. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(3), one Ni(5), and one Ni(7) atom. In the fourteenth O site, O(14) is bonded to one Na(2), one Na(3), one Na(4), one Ni(1), and one Ni(6) atom to form distorted ONa3Ni2 square pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the fifteenth O site, O(15) is bonded to one Na(4), one Ni(4), one Ni(6), and one Ni(7) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid, corners with two equivalent O(16)Na3Ni2 trigonal bipyramids,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(4)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the sixteenth O site, O(16) is bonded to one Na(2), one Na(3), one Na(4), one Ni(2), and one Ni(7) atom to form distorted ONa3Ni2 trigonal bipyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(15)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. is represented by the CIF card [CIF]
data_Na4Ni7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.097
_cell_length_b   7.142
_cell_length_c   7.514
_cell_angle_alpha   68.717
_cell_angle_beta   77.423
_cell_angle_gamma   63.504
_symmetry_Int_Tables_number   1
_cell_volume   316.886
_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
  Na  Na0  1  0.037  0.460  0.669  1.0
  Na  Na1  1  0.598  0.897  0.187  1.0
  Na  Na2  1  0.382  0.633  0.119  1.0
  Na  Na3  1  0.162  0.348  0.103  1.0
  Ni  Ni4  1  0.001  0.004  0.997  1.0
  Ni  Ni5  1  0.624  0.372  0.875  1.0
  Ni  Ni6  1  0.253  0.755  0.743  1.0
  Ni  Ni7  1  0.872  0.120  0.627  1.0
  Ni  Ni8  1  0.501  0.495  0.504  1.0
  Ni  Ni9  1  0.125  0.876  0.375  1.0
  Ni  Ni10  1  0.750  0.244  0.253  1.0
  O  O11  1  0.106  0.722  0.979  1.0
  O  O12  1  0.867  0.304  0.994  1.0
  O  O13  1  0.511  0.672  0.828  1.0
  O  O14  1  0.005  0.826  0.629  1.0
  O  O15  1  0.756  0.072  0.881  1.0
  O  O16  1  0.372  0.454  0.763  1.0
  O  O17  1  0.747  0.413  0.623  1.0
  O  O18  1  0.374  0.797  0.485  1.0
  O  O19  1  0.884  0.947  0.252  1.0
  O  O20  1  0.116  0.056  0.740  1.0
  O  O21  1  0.629  0.197  0.507  1.0
  O  O22  1  0.247  0.575  0.412  1.0
  O  O23  1  0.652  0.524  0.272  1.0
  O  O24  1  0.222  0.972  0.120  1.0
  O  O25  1  0.992  0.171  0.374  1.0
  O  O26  1  0.526  0.285  0.130  1.0
[/CIF]
.
The compound described by Na4Ni7O16 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(7) atom. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(13), one O(14), one O(16), one O(5), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded to one O(1), one O(12), one O(13), one O(14), one O(16), and one O(3) atom to form NaO6 octahedra that share  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the fourth Na site, Na(4) is bonded in a 6-coordinate geometry to one O(1), one O(14), one O(15), one O(16), one O(2), and one O(6) atom. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(10), one O(14), one O(2), one O(5), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(16), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(1), one O(10), one O(3), one O(4), one O(6), and one O(8) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(6)O6 octahedra. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(11), one O(15), one O(4), one O(5), and one O(7) atom to form edge-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded to one O(11), one O(12), one O(13), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(6)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the sixth Ni site, Ni(6) is bonded to one O(12), one O(14), one O(15), one O(4), one O(8), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(7)O6 octahedra. In the seventh Ni site, Ni(7) is bonded to one O(11), one O(13), one O(15), one O(16), one O(2), and one O(9) atom to form NiO6 octahedra that share  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra,  an edgeedge with one Ni(5)O6 octahedra, and  an edgeedge with one Ni(6)O6 octahedra. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(3), one Na(4), one Ni(1), and one Ni(3) atom. In the second O site, O(2) is bonded to one Na(1), one Na(4), one Ni(1), one Ni(2), and one Ni(7) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid,  an edgeedge with one O(7)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Na(3), one Ni(2), and one Ni(3) atom. In the fourth O site, O(4) is bonded to one Na(1), one Ni(3), one Ni(4), and one Ni(6) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid, corners with two equivalent O(7)NaNi3 trigonal pyramids,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Ni(1), one Ni(2), and one Ni(4) atom. In the sixth O site, O(6) is bonded to one Na(1), one Na(4), one Ni(2), one Ni(3), and one Ni(5) atom to form distorted ONa2Ni3 square pyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(4)NaNi3 trigonal pyramid,  an edgeedge with one O(7)NaNi3 trigonal pyramid, and  an edgeedge with one O(8)NaNi3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Na(1), one Ni(2), one Ni(4), and one Ni(5) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(4)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid, and  an edgeedge with one O(6)Na2Ni3 square pyramid. In the eighth O site, O(8) is bonded to one Na(2), one Ni(3), one Ni(5), and one Ni(6) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(15)NaNi3 trigonal pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid, corners with two equivalent O(9)NaNi3 trigonal pyramids,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid, and  an edgeedge with one O(4)NaNi3 trigonal pyramid. In the ninth O site, O(9) is bonded to one Na(2), one Ni(1), one Ni(6), and one Ni(7) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid, corners with two equivalent O(8)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid, and  an edgeedge with one O(15)NaNi3 trigonal pyramid. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Ni(1), one Ni(3), and one Ni(4) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Ni(4), one Ni(5), and one Ni(7) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ni(5), and one Ni(6) atom. In the thirteenth O site, O(13) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(3), one Ni(5), and one Ni(7) atom. In the fourteenth O site, O(14) is bonded to one Na(2), one Na(3), one Na(4), one Ni(1), and one Ni(6) atom to form distorted ONa3Ni2 square pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid,  a cornercorner with one O(16)Na3Ni2 trigonal bipyramid,  a cornercorner with one O(4)NaNi3 trigonal pyramid,  a cornercorner with one O(9)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(16)Na3Ni2 trigonal bipyramid,  an edgeedge with one O(15)NaNi3 trigonal pyramid,  an edgeedge with one O(8)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the fifteenth O site, O(15) is bonded to one Na(4), one Ni(4), one Ni(6), and one Ni(7) atom to form distorted ONaNi3 trigonal pyramids that share  a cornercorner with one O(6)Na2Ni3 square pyramid, corners with two equivalent O(16)Na3Ni2 trigonal bipyramids,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid,  an edgeedge with one O(4)NaNi3 trigonal pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. In the sixteenth O site, O(16) is bonded to one Na(2), one Na(3), one Na(4), one Ni(2), and one Ni(7) atom to form distorted ONa3Ni2 trigonal bipyramids that share  a cornercorner with one O(2)Na2Ni3 square pyramid,  a cornercorner with one O(14)Na3Ni2 square pyramid,  a cornercorner with one O(7)NaNi3 trigonal pyramid,  a cornercorner with one O(8)NaNi3 trigonal pyramid, corners with two equivalent O(15)NaNi3 trigonal pyramids,  an edgeedge with one O(2)Na2Ni3 square pyramid,  an edgeedge with one O(6)Na2Ni3 square pyramid,  an edgeedge with one O(14)Na3Ni2 square pyramid, and  an edgeedge with one O(9)NaNi3 trigonal pyramid. is represented by the CIF card [CIF]
data_Na4Ni7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.097
_cell_length_b   7.142
_cell_length_c   7.514
_cell_angle_alpha   68.717
_cell_angle_beta   77.423
_cell_angle_gamma   63.504
_symmetry_Int_Tables_number   1
_cell_volume   316.886
_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
  Na  Na0  1  0.037  0.460  0.669  1.0
  Na  Na1  1  0.598  0.897  0.187  1.0
  Na  Na2  1  0.382  0.633  0.119  1.0
  Na  Na3  1  0.162  0.348  0.103  1.0
  Ni  Ni4  1  0.001  0.004  0.997  1.0
  Ni  Ni5  1  0.624  0.372  0.875  1.0
  Ni  Ni6  1  0.253  0.755  0.743  1.0
  Ni  Ni7  1  0.872  0.120  0.627  1.0
  Ni  Ni8  1  0.501  0.495  0.504  1.0
  Ni  Ni9  1  0.125  0.876  0.375  1.0
  Ni  Ni10  1  0.750  0.244  0.253  1.0
  O  O11  1  0.106  0.722  0.979  1.0
  O  O12  1  0.867  0.304  0.994  1.0
  O  O13  1  0.511  0.672  0.828  1.0
  O  O14  1  0.005  0.826  0.629  1.0
  O  O15  1  0.756  0.072  0.881  1.0
  O  O16  1  0.372  0.454  0.763  1.0
  O  O17  1  0.747  0.413  0.623  1.0
  O  O18  1  0.374  0.797  0.485  1.0
  O  O19  1  0.884  0.947  0.252  1.0
  O  O20  1  0.116  0.056  0.740  1.0
  O  O21  1  0.629  0.197  0.507  1.0
  O  O22  1  0.247  0.575  0.412  1.0
  O  O23  1  0.652  0.524  0.272  1.0
  O  O24  1  0.222  0.972  0.120  1.0
  O  O25  1  0.992  0.171  0.374  1.0
  O  O26  1  0.526  0.285  0.130  1.0
[/CIF]
.