The material structure described by Sr4Ni3O9 crystallizes in the trigonal P321 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(5), and four equivalent O(3) atoms. In the third Sr site, Sr(3) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), and four equivalent O(4) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(4) and three equivalent O(5) atoms to form face-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form face-sharing NiO6 octahedra. In the third Ni site, Ni(3) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. In the fourth Ni site, Ni(4) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form face-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ni(4) atoms to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 30-54°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), one Ni(3), and one Ni(4) atom. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Ni(2), and one Ni(5) atom to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 4-62°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), one Ni(1), and one Ni(5) atom. In the fifth O site, O(5) is bonded to one Sr(2), one Sr(3), two equivalent Sr(1), one Ni(1), and one Ni(2) atom to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 4-62°. is represented by the CIF card [CIF]
data_Sr4(NiO3)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.543
_cell_length_b   9.543
_cell_length_c   7.834
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   617.863
_cell_formula_units_Z   3
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
  Sr  Sr0  1  0.024  0.691  0.251  1.0
  Sr  Sr1  1  0.000  0.359  0.000  1.0
  Sr  Sr2  1  0.000  0.332  0.500  1.0
  Sr  Sr3  1  0.309  0.333  0.251  1.0
  Sr  Sr4  1  0.333  0.309  0.749  1.0
  Sr  Sr5  1  0.667  0.976  0.251  1.0
  Sr  Sr6  1  0.641  0.641  0.000  1.0
  Sr  Sr7  1  0.332  0.000  0.500  1.0
  Sr  Sr8  1  0.668  0.668  0.500  1.0
  Sr  Sr9  1  0.359  0.000  0.000  1.0
  Sr  Sr10  1  0.976  0.667  0.749  1.0
  Sr  Sr11  1  0.691  0.024  0.749  1.0
  Ni  Ni12  1  0.333  0.667  0.421  1.0
  Ni  Ni13  1  0.333  0.667  0.100  1.0
  Ni  Ni14  1  0.000  0.000  0.000  1.0
  Ni  Ni15  1  0.000  0.000  0.341  1.0
  Ni  Ni16  1  0.000  0.000  0.659  1.0
  Ni  Ni17  1  0.333  0.667  0.760  1.0
  Ni  Ni18  1  0.667  0.333  0.579  1.0
  Ni  Ni19  1  0.667  0.333  0.900  1.0
  Ni  Ni20  1  0.667  0.333  0.240  1.0
  O  O21  1  0.000  0.850  0.500  1.0
  O  O22  1  0.153  0.989  0.801  1.0
  O  O23  1  0.184  0.683  0.959  1.0
  O  O24  1  0.181  0.672  0.562  1.0
  O  O25  1  0.173  0.520  0.259  1.0
  O  O26  1  0.011  0.164  0.801  1.0
  O  O27  1  0.346  0.827  0.259  1.0
  O  O28  1  0.317  0.501  0.959  1.0
  O  O29  1  0.328  0.509  0.562  1.0
  O  O30  1  0.150  0.150  0.500  1.0
  O  O31  1  0.491  0.819  0.562  1.0
  O  O32  1  0.499  0.816  0.959  1.0
  O  O33  1  0.480  0.654  0.259  1.0
  O  O34  1  0.164  0.011  0.199  1.0
  O  O35  1  0.501  0.317  0.041  1.0
  O  O36  1  0.509  0.328  0.438  1.0
  O  O37  1  0.654  0.480  0.741  1.0
  O  O38  1  0.836  0.847  0.801  1.0
  O  O39  1  0.847  0.836  0.199  1.0
  O  O40  1  0.520  0.173  0.741  1.0
  O  O41  1  0.816  0.499  0.041  1.0
  O  O42  1  0.819  0.491  0.438  1.0
  O  O43  1  0.672  0.181  0.438  1.0
  O  O44  1  0.683  0.184  0.041  1.0
  O  O45  1  0.827  0.346  0.741  1.0
  O  O46  1  0.850  0.000  0.500  1.0
  O  O47  1  0.989  0.153  0.199  1.0
[/CIF]
.
The material structure described by Sr4Ni3O9 crystallizes in the trigonal P321 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(5), and four equivalent O(3) atoms. In the third Sr site, Sr(3) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), and four equivalent O(4) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(4) and three equivalent O(5) atoms to form face-sharing NiO6 octahedra. In the second Ni site, Ni(2) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form face-sharing NiO6 octahedra. In the third Ni site, Ni(3) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. In the fourth Ni site, Ni(4) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form face-sharing NiO6 octahedra. In the fifth Ni site, Ni(5) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ni(4) atoms to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 30-54°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Sr(2), one Sr(3), two equivalent Sr(1), one Ni(3), and one Ni(4) atom. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Ni(2), and one Ni(5) atom to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 4-62°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), one Ni(1), and one Ni(5) atom. In the fifth O site, O(5) is bonded to one Sr(2), one Sr(3), two equivalent Sr(1), one Ni(1), and one Ni(2) atom to form a mixture of distorted edge, face, and corner-sharing OSr4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 4-62°. is represented by the CIF card [CIF]
data_Sr4(NiO3)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.543
_cell_length_b   9.543
_cell_length_c   7.834
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   617.863
_cell_formula_units_Z   3
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
  Sr  Sr0  1  0.024  0.691  0.251  1.0
  Sr  Sr1  1  0.000  0.359  0.000  1.0
  Sr  Sr2  1  0.000  0.332  0.500  1.0
  Sr  Sr3  1  0.309  0.333  0.251  1.0
  Sr  Sr4  1  0.333  0.309  0.749  1.0
  Sr  Sr5  1  0.667  0.976  0.251  1.0
  Sr  Sr6  1  0.641  0.641  0.000  1.0
  Sr  Sr7  1  0.332  0.000  0.500  1.0
  Sr  Sr8  1  0.668  0.668  0.500  1.0
  Sr  Sr9  1  0.359  0.000  0.000  1.0
  Sr  Sr10  1  0.976  0.667  0.749  1.0
  Sr  Sr11  1  0.691  0.024  0.749  1.0
  Ni  Ni12  1  0.333  0.667  0.421  1.0
  Ni  Ni13  1  0.333  0.667  0.100  1.0
  Ni  Ni14  1  0.000  0.000  0.000  1.0
  Ni  Ni15  1  0.000  0.000  0.341  1.0
  Ni  Ni16  1  0.000  0.000  0.659  1.0
  Ni  Ni17  1  0.333  0.667  0.760  1.0
  Ni  Ni18  1  0.667  0.333  0.579  1.0
  Ni  Ni19  1  0.667  0.333  0.900  1.0
  Ni  Ni20  1  0.667  0.333  0.240  1.0
  O  O21  1  0.000  0.850  0.500  1.0
  O  O22  1  0.153  0.989  0.801  1.0
  O  O23  1  0.184  0.683  0.959  1.0
  O  O24  1  0.181  0.672  0.562  1.0
  O  O25  1  0.173  0.520  0.259  1.0
  O  O26  1  0.011  0.164  0.801  1.0
  O  O27  1  0.346  0.827  0.259  1.0
  O  O28  1  0.317  0.501  0.959  1.0
  O  O29  1  0.328  0.509  0.562  1.0
  O  O30  1  0.150  0.150  0.500  1.0
  O  O31  1  0.491  0.819  0.562  1.0
  O  O32  1  0.499  0.816  0.959  1.0
  O  O33  1  0.480  0.654  0.259  1.0
  O  O34  1  0.164  0.011  0.199  1.0
  O  O35  1  0.501  0.317  0.041  1.0
  O  O36  1  0.509  0.328  0.438  1.0
  O  O37  1  0.654  0.480  0.741  1.0
  O  O38  1  0.836  0.847  0.801  1.0
  O  O39  1  0.847  0.836  0.199  1.0
  O  O40  1  0.520  0.173  0.741  1.0
  O  O41  1  0.816  0.499  0.041  1.0
  O  O42  1  0.819  0.491  0.438  1.0
  O  O43  1  0.672  0.181  0.438  1.0
  O  O44  1  0.683  0.184  0.041  1.0
  O  O45  1  0.827  0.346  0.741  1.0
  O  O46  1  0.850  0.000  0.500  1.0
  O  O47  1  0.989  0.153  0.199  1.0
[/CIF]
.