The structure described by Ca3Ni2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Ni(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_Ca3Ni2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.371
_cell_length_b   5.343
_cell_length_c   9.991
_cell_angle_alpha   105.508
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   276.310
_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
  Ca  Ca0  1  0.702  0.762  0.000  1.0
  Ca  Ca1  1  0.202  0.238  0.000  1.0
  Ca  Ca2  1  0.791  0.573  0.631  1.0
  Ca  Ca3  1  0.291  0.427  0.369  1.0
  Ca  Ca4  1  0.791  0.942  0.369  1.0
  Ca  Ca5  1  0.291  0.058  0.631  1.0
  Ni  Ni6  1  0.749  0.347  0.195  1.0
  Ni  Ni7  1  0.249  0.653  0.805  1.0
  Ni  Ni8  1  0.249  0.848  0.195  1.0
  Ni  Ni9  1  0.749  0.152  0.805  1.0
  O  O10  1  0.747  0.006  0.607  1.0
  O  O11  1  0.247  0.994  0.393  1.0
  O  O12  1  0.247  0.601  0.607  1.0
  O  O13  1  0.747  0.399  0.393  1.0
  O  O14  1  0.034  0.349  0.775  1.0
  O  O15  1  0.534  0.651  0.225  1.0
  O  O16  1  0.534  0.426  0.775  1.0
  O  O17  1  0.034  0.574  0.225  1.0
  O  O18  1  0.959  0.874  0.834  1.0
  O  O19  1  0.459  0.126  0.166  1.0
  O  O20  1  0.760  0.328  0.000  1.0
  O  O21  1  0.260  0.672  0.000  1.0
  O  O22  1  0.959  0.041  0.166  1.0
  O  O23  1  0.459  0.959  0.834  1.0
[/CIF]
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The structure described by Ca3Ni2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-25°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Ni(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_Ca3Ni2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.371
_cell_length_b   5.343
_cell_length_c   9.991
_cell_angle_alpha   105.508
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   276.310
_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
  Ca  Ca0  1  0.702  0.762  0.000  1.0
  Ca  Ca1  1  0.202  0.238  0.000  1.0
  Ca  Ca2  1  0.791  0.573  0.631  1.0
  Ca  Ca3  1  0.291  0.427  0.369  1.0
  Ca  Ca4  1  0.791  0.942  0.369  1.0
  Ca  Ca5  1  0.291  0.058  0.631  1.0
  Ni  Ni6  1  0.749  0.347  0.195  1.0
  Ni  Ni7  1  0.249  0.653  0.805  1.0
  Ni  Ni8  1  0.249  0.848  0.195  1.0
  Ni  Ni9  1  0.749  0.152  0.805  1.0
  O  O10  1  0.747  0.006  0.607  1.0
  O  O11  1  0.247  0.994  0.393  1.0
  O  O12  1  0.247  0.601  0.607  1.0
  O  O13  1  0.747  0.399  0.393  1.0
  O  O14  1  0.034  0.349  0.775  1.0
  O  O15  1  0.534  0.651  0.225  1.0
  O  O16  1  0.534  0.426  0.775  1.0
  O  O17  1  0.034  0.574  0.225  1.0
  O  O18  1  0.959  0.874  0.834  1.0
  O  O19  1  0.459  0.126  0.166  1.0
  O  O20  1  0.760  0.328  0.000  1.0
  O  O21  1  0.260  0.672  0.000  1.0
  O  O22  1  0.959  0.041  0.166  1.0
  O  O23  1  0.459  0.959  0.834  1.0
[/CIF]
.