The structure described by Eu2NiO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Eu(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(2) is bonded to five equivalent Eu(1) and one Ni(1) atom to form distorted OEu5Ni octahedra that share corners with five equivalent O(2)Eu5Ni octahedra, corners with twelve equivalent O(1)Eu4Ni2 octahedra, edges with eight equivalent O(2)Eu5Ni octahedra, and faces with four equivalent O(1)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-52°. In the second O site, O(1) is bonded to four equivalent Eu(1) and two equivalent Ni(1) atoms to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with twelve equivalent O(2)Eu5Ni octahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, faces with four equivalent O(1)Eu4Ni2 octahedra, and faces with four equivalent O(2)Eu5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-52°. is represented by the CIF file [CIF]
data_Eu2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.685
_cell_length_b   6.685
_cell_length_c   6.685
_cell_angle_alpha   147.019
_cell_angle_beta   147.019
_cell_angle_gamma   47.335
_symmetry_Int_Tables_number   1
_cell_volume   88.174
_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
  Eu  Eu0  1  0.643  0.643  0.000  1.0
  Eu  Eu1  1  0.357  0.357  0.000  1.0
  Ni  Ni2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.000  0.500  0.500  1.0
  O  O4  1  0.500  0.000  0.500  1.0
  O  O5  1  0.175  0.175  0.000  1.0
  O  O6  1  0.825  0.825  0.000  1.0
[/CIF]
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The structure described by Eu2NiO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Eu(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(2) is bonded to five equivalent Eu(1) and one Ni(1) atom to form distorted OEu5Ni octahedra that share corners with five equivalent O(2)Eu5Ni octahedra, corners with twelve equivalent O(1)Eu4Ni2 octahedra, edges with eight equivalent O(2)Eu5Ni octahedra, and faces with four equivalent O(1)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-52°. In the second O site, O(1) is bonded to four equivalent Eu(1) and two equivalent Ni(1) atoms to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with twelve equivalent O(2)Eu5Ni octahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, faces with four equivalent O(1)Eu4Ni2 octahedra, and faces with four equivalent O(2)Eu5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-52°. is represented by the CIF file [CIF]
data_Eu2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.685
_cell_length_b   6.685
_cell_length_c   6.685
_cell_angle_alpha   147.019
_cell_angle_beta   147.019
_cell_angle_gamma   47.335
_symmetry_Int_Tables_number   1
_cell_volume   88.174
_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
  Eu  Eu0  1  0.643  0.643  0.000  1.0
  Eu  Eu1  1  0.357  0.357  0.000  1.0
  Ni  Ni2  1  0.000  0.000  0.000  1.0
  O  O3  1  0.000  0.500  0.500  1.0
  O  O4  1  0.500  0.000  0.500  1.0
  O  O5  1  0.175  0.175  0.000  1.0
  O  O6  1  0.825  0.825  0.000  1.0
[/CIF]
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