data_FeCo3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.25
_cell_length_b   4.25
_cell_length_c   4.25
_cell_angle_alpha   131.81
_cell_angle_beta   131.81
_cell_angle_gamma   70.52
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCo3
_chemical_formula_sum   'Fe1 Co3'
_cell_volume   41.85
_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
  Fe  Fe3  1  0.0  0.0  0.0  1.0
  Co  Co0  1  0.74  0.0  0.74  1.0
  Co  Co1  1  0.0  0.74  0.74  1.0
  Co  Co2  1  0.0  0.0  0.47  1.0

data_FeCo3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.91
_cell_length_b   4.91
_cell_length_c   4.25
_cell_angle_alpha   90.0
_cell_angle_beta   125.26
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   FeCo3
_chemical_formula_sum   'Fe2 Co6'
_cell_volume   83.71
_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
  Fe  Fe0  2  0.0  0.0  0.0  1.0
  Co  Co1  4  0.13  0.13  0.0  1.0
  Co  Co2  2  0.0  0.0  0.47  1.0

Fe Co Co Co
Fe Co Co Co 0 1 - o - 0 2 o - - 0 3 o o o 0 3 o o - 1 3 + o o 2 3 o + o 
FeCo3 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two FeCo3 clusters. Fe(1) is bonded in a distorted L-shaped geometry to one Co(2) and two equivalent Co(1) atoms. The Fe(1)-Co(2) bond length is 2.01 Å. Both Fe(1)-Co(1) bond lengths are 0.92 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a single-bond geometry to one Fe(1) atom. In the second Co site, Co(2) is bonded in a 1-coordinate geometry to one Fe(1) atom.