The structure described by Ba3NiO4 crystallizes in the trigonal R-3c space group. Ba(1) is bonded to two equivalent O(2) and five equivalent O(1) atoms to form a mixture of distorted corner, edge, and face-sharing BaO7 pentagonal bipyramids. Ni(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Ba(1) and one Ni(1) atom to form distorted OBa5Ni octahedra that share corners with four equivalent O(2)Ba6 octahedra, corners with six equivalent O(1)Ba5Ni octahedra, edges with eight equivalent O(1)Ba5Ni octahedra, and faces with two equivalent O(2)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 10-72°. In the second O site, O(2) is bonded to six equivalent Ba(1) atoms to form OBa6 octahedra that share corners with six equivalent O(2)Ba6 octahedra, corners with twelve equivalent O(1)Ba5Ni octahedra, and faces with six equivalent O(1)Ba5Ni octahedra. The corner-sharing octahedral tilt angles range from 28-72°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.245
_cell_length_b   7.245
_cell_length_c   7.245
_cell_angle_alpha   66.619
_cell_angle_beta   66.619
_cell_angle_gamma   66.619
_symmetry_Int_Tables_number   1
_cell_volume   307.153
_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
  Ba  Ba0  1  0.750  0.335  0.165  1.0
  Ba  Ba1  1  0.165  0.750  0.335  1.0
  Ba  Ba2  1  0.250  0.665  0.835  1.0
  Ba  Ba3  1  0.665  0.835  0.250  1.0
  Ba  Ba4  1  0.835  0.250  0.665  1.0
  Ba  Ba5  1  0.335  0.165  0.750  1.0
  Ni  Ni6  1  0.750  0.750  0.750  1.0
  Ni  Ni7  1  0.250  0.250  0.250  1.0
  O  O8  1  0.750  0.983  0.517  1.0
  O  O9  1  0.483  0.250  0.017  1.0
  O  O10  1  0.000  0.000  0.000  1.0
  O  O11  1  0.500  0.500  0.500  1.0
  O  O12  1  0.017  0.483  0.250  1.0
  O  O13  1  0.517  0.750  0.983  1.0
  O  O14  1  0.250  0.017  0.483  1.0
  O  O15  1  0.983  0.517  0.750  1.0
[/CIF]
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The structure described by Ba3NiO4 crystallizes in the trigonal R-3c space group. Ba(1) is bonded to two equivalent O(2) and five equivalent O(1) atoms to form a mixture of distorted corner, edge, and face-sharing BaO7 pentagonal bipyramids. Ni(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Ba(1) and one Ni(1) atom to form distorted OBa5Ni octahedra that share corners with four equivalent O(2)Ba6 octahedra, corners with six equivalent O(1)Ba5Ni octahedra, edges with eight equivalent O(1)Ba5Ni octahedra, and faces with two equivalent O(2)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 10-72°. In the second O site, O(2) is bonded to six equivalent Ba(1) atoms to form OBa6 octahedra that share corners with six equivalent O(2)Ba6 octahedra, corners with twelve equivalent O(1)Ba5Ni octahedra, and faces with six equivalent O(1)Ba5Ni octahedra. The corner-sharing octahedral tilt angles range from 28-72°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.245
_cell_length_b   7.245
_cell_length_c   7.245
_cell_angle_alpha   66.619
_cell_angle_beta   66.619
_cell_angle_gamma   66.619
_symmetry_Int_Tables_number   1
_cell_volume   307.153
_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
  Ba  Ba0  1  0.750  0.335  0.165  1.0
  Ba  Ba1  1  0.165  0.750  0.335  1.0
  Ba  Ba2  1  0.250  0.665  0.835  1.0
  Ba  Ba3  1  0.665  0.835  0.250  1.0
  Ba  Ba4  1  0.835  0.250  0.665  1.0
  Ba  Ba5  1  0.335  0.165  0.750  1.0
  Ni  Ni6  1  0.750  0.750  0.750  1.0
  Ni  Ni7  1  0.250  0.250  0.250  1.0
  O  O8  1  0.750  0.983  0.517  1.0
  O  O9  1  0.483  0.250  0.017  1.0
  O  O10  1  0.000  0.000  0.000  1.0
  O  O11  1  0.500  0.500  0.500  1.0
  O  O12  1  0.017  0.483  0.250  1.0
  O  O13  1  0.517  0.750  0.983  1.0
  O  O14  1  0.250  0.017  0.483  1.0
  O  O15  1  0.983  0.517  0.750  1.0
[/CIF]
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