The material structure described by La2Ni2O5 crystallizes in the monoclinic C2/c space group. La(1) is bonded in a 7-coordinate geometry to one O(1), three equivalent O(2), and three equivalent O(3) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 29°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Ni(2) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent La(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent La(1), one Ni(1), and one Ni(2) atom. is represented by the CIF file [CIF]
data_La2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.601
_cell_length_b   5.601
_cell_length_c   7.558
_cell_angle_alpha   85.751
_cell_angle_beta   85.751
_cell_angle_gamma   90.665
_symmetry_Int_Tables_number   1
_cell_volume   235.799
_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
  La  La0  1  0.516  0.978  0.251  1.0
  La  La1  1  0.022  0.484  0.249  1.0
  La  La2  1  0.484  0.022  0.749  1.0
  La  La3  1  0.978  0.516  0.751  1.0
  Ni  Ni4  1  0.500  0.500  0.500  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  Ni  Ni6  1  0.000  0.000  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.939  0.061  0.250  1.0
  O  O9  1  0.061  0.939  0.750  1.0
  O  O10  1  0.231  0.695  0.455  1.0
  O  O11  1  0.305  0.769  0.045  1.0
  O  O12  1  0.769  0.305  0.545  1.0
  O  O13  1  0.695  0.231  0.955  1.0
  O  O14  1  0.314  0.228  0.461  1.0
  O  O15  1  0.772  0.686  0.039  1.0
  O  O16  1  0.228  0.314  0.961  1.0
  O  O17  1  0.686  0.772  0.539  1.0
[/CIF]
.
The material structure described by La2Ni2O5 crystallizes in the monoclinic C2/c space group. La(1) is bonded in a 7-coordinate geometry to one O(1), three equivalent O(2), and three equivalent O(3) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 29°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Ni(2) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent La(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent La(1), one Ni(1), and one Ni(2) atom. is represented by the CIF file [CIF]
data_La2Ni2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.601
_cell_length_b   5.601
_cell_length_c   7.558
_cell_angle_alpha   85.751
_cell_angle_beta   85.751
_cell_angle_gamma   90.665
_symmetry_Int_Tables_number   1
_cell_volume   235.799
_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
  La  La0  1  0.516  0.978  0.251  1.0
  La  La1  1  0.022  0.484  0.249  1.0
  La  La2  1  0.484  0.022  0.749  1.0
  La  La3  1  0.978  0.516  0.751  1.0
  Ni  Ni4  1  0.500  0.500  0.500  1.0
  Ni  Ni5  1  0.500  0.500  0.000  1.0
  Ni  Ni6  1  0.000  0.000  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.939  0.061  0.250  1.0
  O  O9  1  0.061  0.939  0.750  1.0
  O  O10  1  0.231  0.695  0.455  1.0
  O  O11  1  0.305  0.769  0.045  1.0
  O  O12  1  0.769  0.305  0.545  1.0
  O  O13  1  0.695  0.231  0.955  1.0
  O  O14  1  0.314  0.228  0.461  1.0
  O  O15  1  0.772  0.686  0.039  1.0
  O  O16  1  0.228  0.314  0.961  1.0
  O  O17  1  0.686  0.772  0.539  1.0
[/CIF]
.