data_Mg2Nb2CuO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.03
_cell_length_b   10.03
_cell_length_c   5.17
_cell_angle_alpha   91.64
_cell_angle_beta   91.64
_cell_angle_gamma   35.26
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Nb2CuO8
_chemical_formula_sum   'Mg4 Nb4 Cu2 O16'
_cell_volume   299.65
_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
  Mg  Mg0  1  0.08  0.14  0.88  1.0
  Mg  Mg1  1  0.8  0.14  0.86  1.0
  Mg  Mg2  1  0.88  0.86  0.28  1.0
  Mg  Mg3  1  0.15  0.86  0.3  1.0
  Nb  Nb4  1  0.65  0.04  0.8  1.0
  Nb  Nb5  1  0.23  0.04  0.95  1.0
  Nb  Nb6  1  0.31  0.96  0.37  1.0
  Nb  Nb7  1  0.73  0.96  0.22  1.0
  Cu  Cu8  1  0.44  0.08  0.87  1.0
  Cu  Cu9  1  0.52  0.92  0.29  1.0
  O  O10  1  0.92  0.36  0.36  1.0
  O  O11  1  0.11  0.36  0.23  1.0
  O  O12  1  0.03  0.64  0.81  1.0
  O  O13  1  0.85  0.64  0.94  1.0
  O  O14  1  0.55  0.83  0.9  1.0
  O  O15  1  0.33  0.83  0.85  1.0
  O  O16  1  0.41  0.17  0.27  1.0
  O  O17  1  0.62  0.17  0.32  1.0
  O  O18  1  0.51  0.38  0.34  1.0
  O  O19  1  0.52  0.38  0.24  1.0
  O  O20  1  0.15  0.13  0.95  1.0
  O  O21  1  0.88  0.13  0.63  1.0
  O  O22  1  0.8  0.87  0.21  1.0
  O  O23  1  0.07  0.87  0.53  1.0
  O  O24  1  0.44  0.62  0.92  1.0
  O  O25  1  0.44  0.62  0.82  1.0

data_Mg2Nb2CuO8
_symmetry_space_group_name_H-M   P-1
_cell_length_a   5.17
_cell_length_b   6.07
_cell_length_c   10.03
_cell_angle_alpha   107.63
_cell_angle_beta   91.64
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Mg2Nb2CuO8
_chemical_formula_sum   'Mg4 Nb4 Cu2 O16'
_cell_volume   299.65
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Mg  Mg0  2  0.28  0.14  0.96  1.0
  Mg  Mg1  2  0.3  0.14  0.24  1.0
  Nb  Nb2  2  0.22  0.04  0.71  1.0
  Nb  Nb3  2  0.37  0.04  0.29  1.0
  Cu  Cu4  2  0.29  0.08  0.54  1.0
  O  O5  2  0.05  0.13  0.03  1.0
  O  O6  2  0.23  0.64  0.7  1.0
  O  O7  2  0.24  0.62  0.08  1.0
  O  O8  2  0.27  0.83  0.19  1.0
  O  O9  2  0.32  0.83  0.4  1.0
  O  O10  2  0.34  0.62  0.08  1.0
  O  O11  2  0.36  0.64  0.51  1.0
  O  O12  2  0.37  0.13  0.3  1.0

Mg Mg Mg Mg Nb Nb Nb Nb Cu Cu O O O O O O O O O O O O O O O O