data_FeCo2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.27
_cell_length_b   4.27
_cell_length_c   2.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   109.92
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCo2Se
_chemical_formula_sum   'Fe1 Co2 Se1'
_cell_volume   46.87
_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  Fe2  1  0.0  0.0  0.0  1.0
  Co  Co0  1  0.23  0.25  0.37  1.0
  Co  Co1  1  0.23  0.75  0.37  1.0
  Se  Se3  1  0.45  0.0  0.0  1.0

data_FeCo2Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.74
_cell_length_b   4.27
_cell_length_c   4.27
_cell_angle_alpha   109.92
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCo2Se
_chemical_formula_sum   'Fe1 Co2 Se1'
_cell_volume   46.87
_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  Fe0  1  0.0  0.0  0.0  1.0
  Co  Co1  1  0.37  0.23  0.25  1.0
  Co  Co2  1  0.37  0.23  0.75  1.0
  Se  Se3  1  -0.0  0.45  0.0  1.0

Fe Co Co Se
FeCo2Se crystallizes in the triclinic P1 space group. Fe(1) is bonded in a 3-coordinate geometry to two equivalent Co(1) and two equivalent Se(1) atoms. There is one shorter (1.55 Å) and one longer (2.09 Å) Fe(1)-Co(1) bond length. There is one shorter (1.92 Å) and one longer (2.35 Å) Fe(1)-Se(1) bond length. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 5-coordinate geometry to two equivalent Fe(1), one Co(2), and two equivalent Se(1) atoms. The Co(1)-Co(2) bond length is 2.11 Å. There is one shorter (1.95 Å) and one longer (2.40 Å) Co(1)-Se(1) bond length. In the second Co site, Co(2) is bonded in a 1-coordinate geometry to one Co(1) and one Se(1) atom. The Co(2)-Se(1) bond length is 1.55 Å. Se(1) is bonded in a 1-coordinate geometry to two equivalent Fe(1), one Co(2), and two equivalent Co(1) atoms.