The structure described by Eu2Ni2O5 crystallizes in the orthorhombic Ima2 space group. Eu(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 13°. In the second Ni site, Ni(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first 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 four equivalent O(3)Eu2Ni2 tetrahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, and faces with four equivalent O(1)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Eu(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded to two equivalent Eu(1) and two equivalent Ni(2) atoms to form OEu2Ni2 tetrahedra that share corners with eight equivalent O(1)Eu4Ni2 octahedra and corners with two equivalent O(3)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 24-73°. is represented by the CIF file [CIF]
data_Eu2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.691
_cell_length_b   8.691
_cell_length_c   8.691
_cell_angle_alpha   144.396
_cell_angle_beta   142.702
_cell_angle_gamma   52.515
_symmetry_Int_Tables_number   1
_cell_volume   230.205
_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
  Eu  Eu0  1  0.872  0.387  0.478  1.0
  Eu  Eu1  1  0.128  0.606  0.514  1.0
  Eu  Eu2  1  0.408  0.887  0.514  1.0
  Eu  Eu3  1  0.592  0.106  0.478  1.0
  Ni  Ni4  1  0.000  0.988  0.988  1.0
  Ni  Ni5  1  0.500  0.488  0.988  1.0
  Ni  Ni6  1  0.808  0.780  0.088  1.0
  Ni  Ni7  1  0.192  0.280  0.972  1.0
  O  O8  1  0.760  0.755  0.488  1.0
  O  O9  1  0.240  0.728  0.995  1.0
  O  O10  1  0.767  0.255  0.995  1.0
  O  O11  1  0.233  0.228  0.488  1.0
  O  O12  1  0.802  0.833  0.904  1.0
  O  O13  1  0.198  0.103  0.031  1.0
  O  O14  1  0.429  0.333  0.031  1.0
  O  O15  1  0.571  0.603  0.904  1.0
  O  O16  1  0.851  0.157  0.508  1.0
  O  O17  1  0.149  0.657  0.306  1.0
[/CIF]
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The structure described by Eu2Ni2O5 crystallizes in the orthorhombic Ima2 space group. Eu(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 13°. In the second Ni site, Ni(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and corners with two equivalent Ni(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first 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 four equivalent O(3)Eu2Ni2 tetrahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, and faces with four equivalent O(1)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Eu(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded to two equivalent Eu(1) and two equivalent Ni(2) atoms to form OEu2Ni2 tetrahedra that share corners with eight equivalent O(1)Eu4Ni2 octahedra and corners with two equivalent O(3)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 24-73°. is represented by the CIF file [CIF]
data_Eu2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.691
_cell_length_b   8.691
_cell_length_c   8.691
_cell_angle_alpha   144.396
_cell_angle_beta   142.702
_cell_angle_gamma   52.515
_symmetry_Int_Tables_number   1
_cell_volume   230.205
_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
  Eu  Eu0  1  0.872  0.387  0.478  1.0
  Eu  Eu1  1  0.128  0.606  0.514  1.0
  Eu  Eu2  1  0.408  0.887  0.514  1.0
  Eu  Eu3  1  0.592  0.106  0.478  1.0
  Ni  Ni4  1  0.000  0.988  0.988  1.0
  Ni  Ni5  1  0.500  0.488  0.988  1.0
  Ni  Ni6  1  0.808  0.780  0.088  1.0
  Ni  Ni7  1  0.192  0.280  0.972  1.0
  O  O8  1  0.760  0.755  0.488  1.0
  O  O9  1  0.240  0.728  0.995  1.0
  O  O10  1  0.767  0.255  0.995  1.0
  O  O11  1  0.233  0.228  0.488  1.0
  O  O12  1  0.802  0.833  0.904  1.0
  O  O13  1  0.198  0.103  0.031  1.0
  O  O14  1  0.429  0.333  0.031  1.0
  O  O15  1  0.571  0.603  0.904  1.0
  O  O16  1  0.851  0.157  0.508  1.0
  O  O17  1  0.149  0.657  0.306  1.0
[/CIF]
.