data_Ba2FeCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.57
_cell_length_b   3.57
_cell_length_c   9.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2FeCu
_chemical_formula_sum   'Ba2 Fe1 Cu1'
_cell_volume   115.02
_cell_formula_units_Z   1
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
  Ba  Ba0  1  0.79  0.79  0.17  1.0
  Ba  Ba1  1  0.0  0.0  0.14  1.0
  Fe  Fe3  1  0.0  0.0  0.88  1.0
  Cu  Cu2  1  0.79  0.79  0.3  1.0

data_Ba2FeCu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   9.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2FeCu
_chemical_formula_sum   'Ba4 Fe2 Cu2'
_cell_volume   230.05
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Ba  Ba0  2  0.0  0.0  0.14  1.0
  Ba  Ba1  2  0.29  0.5  0.17  1.0
  Fe  Fe2  2  0.0  0.0  0.88  1.0
  Cu  Cu3  2  0.29  0.5  0.3  1.0

Ba Ba Fe Cu
Ba Ba Fe Cu 0 1 + + o 0 3 o o o 1 2 o o - 
Ba2FeCu crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ba2FeCu clusters. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a distorted single-bond geometry to one Ba(2) and one Cu(1) atom. The Ba(1)-Ba(2) bond length is 1.12 Å. The Ba(1)-Cu(1) bond length is 1.14 Å. In the second Ba site, Ba(2) is bonded in a distorted water-like geometry to one Ba(1) and one Fe(1) atom. The Ba(2)-Fe(1) bond length is 2.30 Å. Fe(1) is bonded in a single-bond geometry to one Ba(2) atom. Cu(1) is bonded in a single-bond geometry to one Ba(1) atom.