The material structure described by Eu2Ni2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), one O(9), and two equivalent O(5) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(8), and two equivalent O(6) atoms. In the third Eu site, Eu(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and two equivalent O(7) atoms. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(9), and two equivalent O(8) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share corners with four equivalent Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O4 tetrahedra, and  a cornercorner with one Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O4 tetrahedra, and  a cornercorner with one Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the third Ni site, Ni(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form NiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form NiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Ni(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(4)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(4)Eu4Ni2 octahedra, faces with two equivalent O(2)Eu4Ni2 octahedra, and faces with two equivalent O(3)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(3)Eu4Ni2 octahedra, faces with two equivalent O(1)Eu4Ni2 octahedra, and faces with two equivalent O(4)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(2)Eu4Ni2 octahedra, faces with two equivalent O(1)Eu4Ni2 octahedra, and faces with two equivalent O(4)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the fourth O site, O(4) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, faces with two equivalent O(2)Eu4Ni2 octahedra, and faces with two equivalent O(3)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Eu(3), two equivalent Eu(1), one Ni(1), and one Ni(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Eu(4), two equivalent Eu(2), one Ni(1), and one Ni(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Eu(1), two equivalent Eu(3), one Ni(2), and one Ni(4) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Eu(2), two equivalent Eu(4), one Ni(2), and one Ni(3) atom. In the ninth O site, O(9) is bonded to one Eu(1), one Eu(4), one Ni(3), and one Ni(4) atom to form distorted OEu2Ni2 tetrahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(4)Eu4Ni2 octahedra, and corners with two equivalent O(10)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 22-78°. In the tenth O site, O(10) is bonded to one Eu(2), one Eu(3), one Ni(3), and one Ni(4) atom to form distorted OEu2Ni2 tetrahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(4)Eu4Ni2 octahedra, and corners with two equivalent O(9)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-78°. is represented by the CIF file [CIF]
data_Eu2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.380
_cell_length_b   5.664
_cell_length_c   8.662
_cell_angle_alpha   109.090
_cell_angle_beta   107.747
_cell_angle_gamma   89.855
_symmetry_Int_Tables_number   1
_cell_volume   236.177
_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  0.400  0.912  0.784  1.0
  Eu  Eu1  1  0.613  0.087  0.217  1.0
  Eu  Eu2  1  0.898  0.370  0.782  1.0
  Eu  Eu3  1  0.113  0.628  0.216  1.0
  Ni  Ni4  1  0.995  0.999  0.993  1.0
  Ni  Ni5  1  0.501  0.505  0.005  1.0
  Ni  Ni6  1  0.790  0.688  0.500  1.0
  Ni  Ni7  1  0.294  0.318  0.500  1.0
  O  O8  1  0.765  0.269  0.027  1.0
  O  O9  1  0.739  0.734  0.974  1.0
  O  O10  1  0.265  0.259  0.026  1.0
  O  O11  1  0.237  0.740  0.973  1.0
  O  O12  1  0.840  0.932  0.727  1.0
  O  O13  1  0.116  0.078  0.289  1.0
  O  O14  1  0.328  0.287  0.711  1.0
  O  O15  1  0.610  0.704  0.273  1.0
  O  O16  1  0.164  0.629  0.502  1.0
  O  O17  1  0.646  0.362  0.500  1.0
[/CIF]
.
The material structure described by Eu2Ni2O5 crystallizes in the triclinic P1 space group. There are four inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), one O(9), and two equivalent O(5) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(8), and two equivalent O(6) atoms. In the third Eu site, Eu(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), and two equivalent O(7) atoms. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(9), and two equivalent O(8) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share corners with four equivalent Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O4 tetrahedra, and  a cornercorner with one Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the second Ni site, Ni(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O4 tetrahedra, and  a cornercorner with one Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the third Ni site, Ni(3) is bonded to one O(10), one O(5), one O(8), and one O(9) atom to form NiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Ni(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. In the fourth Ni site, Ni(4) is bonded to one O(10), one O(6), one O(7), and one O(9) atom to form NiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Ni(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(4)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(4)Eu4Ni2 octahedra, faces with two equivalent O(2)Eu4Ni2 octahedra, and faces with two equivalent O(3)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(3)Eu4Ni2 octahedra, faces with two equivalent O(1)Eu4Ni2 octahedra, and faces with two equivalent O(4)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(2)Eu4Ni2 octahedra, faces with two equivalent O(1)Eu4Ni2 octahedra, and faces with two equivalent O(4)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the fourth O site, O(4) is bonded to one Eu(1), one Eu(2), one Eu(3), one Eu(4), one Ni(1), and one Ni(2) atom to form distorted OEu4Ni2 octahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(10)Eu2Ni2 tetrahedra, corners with two equivalent O(9)Eu2Ni2 tetrahedra, edges with two equivalent O(1)Eu4Ni2 octahedra, faces with two equivalent O(2)Eu4Ni2 octahedra, and faces with two equivalent O(3)Eu4Ni2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Eu(3), two equivalent Eu(1), one Ni(1), and one Ni(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Eu(4), two equivalent Eu(2), one Ni(1), and one Ni(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Eu(1), two equivalent Eu(3), one Ni(2), and one Ni(4) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Eu(2), two equivalent Eu(4), one Ni(2), and one Ni(3) atom. In the ninth O site, O(9) is bonded to one Eu(1), one Eu(4), one Ni(3), and one Ni(4) atom to form distorted OEu2Ni2 tetrahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(4)Eu4Ni2 octahedra, and corners with two equivalent O(10)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 22-78°. In the tenth O site, O(10) is bonded to one Eu(2), one Eu(3), one Ni(3), and one Ni(4) atom to form distorted OEu2Ni2 tetrahedra that share corners with two equivalent O(1)Eu4Ni2 octahedra, corners with two equivalent O(2)Eu4Ni2 octahedra, corners with two equivalent O(3)Eu4Ni2 octahedra, corners with two equivalent O(4)Eu4Ni2 octahedra, and corners with two equivalent O(9)Eu2Ni2 tetrahedra. The corner-sharing octahedral tilt angles range from 21-78°. is represented by the CIF file [CIF]
data_Eu2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.380
_cell_length_b   5.664
_cell_length_c   8.662
_cell_angle_alpha   109.090
_cell_angle_beta   107.747
_cell_angle_gamma   89.855
_symmetry_Int_Tables_number   1
_cell_volume   236.177
_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  0.400  0.912  0.784  1.0
  Eu  Eu1  1  0.613  0.087  0.217  1.0
  Eu  Eu2  1  0.898  0.370  0.782  1.0
  Eu  Eu3  1  0.113  0.628  0.216  1.0
  Ni  Ni4  1  0.995  0.999  0.993  1.0
  Ni  Ni5  1  0.501  0.505  0.005  1.0
  Ni  Ni6  1  0.790  0.688  0.500  1.0
  Ni  Ni7  1  0.294  0.318  0.500  1.0
  O  O8  1  0.765  0.269  0.027  1.0
  O  O9  1  0.739  0.734  0.974  1.0
  O  O10  1  0.265  0.259  0.026  1.0
  O  O11  1  0.237  0.740  0.973  1.0
  O  O12  1  0.840  0.932  0.727  1.0
  O  O13  1  0.116  0.078  0.289  1.0
  O  O14  1  0.328  0.287  0.711  1.0
  O  O15  1  0.610  0.704  0.273  1.0
  O  O16  1  0.164  0.629  0.502  1.0
  O  O17  1  0.646  0.362  0.500  1.0
[/CIF]
.