data_BaFe2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.76
_cell_length_b   5.76
_cell_length_c   5.76
_cell_angle_alpha   149.91
_cell_angle_beta   123.62
_cell_angle_gamma   65.23
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaFe2Si
_chemical_formula_sum   'Ba1 Fe2 Si1'
_cell_volume   78.95
_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  0.0  0.72  0.41  1.0
  Fe  Fe1  1  0.0  0.0  0.54  1.0
  Fe  Fe2  1  0.49  0.0  0.39  1.0
  Si  Si3  1  0.0  0.0  0.36  1.0

data_BaFe2Si
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.99
_cell_length_b   5.44
_cell_length_c   5.76
_cell_angle_alpha   118.19
_cell_angle_beta   105.04
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaFe2Si
_chemical_formula_sum   'Ba1 Fe2 Si1'
_cell_volume   78.95
_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  0.28  0.69  0.69  1.0
  Fe  Fe1  1  0.0  0.39  0.9  1.0
  Fe  Fe2  1  0.0  0.54  0.54  1.0
  Si  Si3  1  0.0  0.36  0.36  1.0

Ba Fe Fe Si
BaFe2Si crystallizes in the triclinic P1 space group. Ba(1) is bonded in a single-bond geometry to one Fe(1) and four equivalent Fe(2) atoms. The Ba(1)-Fe(1) bond length is 1.02 Å. There are a spread of Ba(1)-Fe(2) bond distances ranging from 2.66-3.89 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one Ba(1), one Fe(2), and one Si(1) atom. The Fe(1)-Fe(2) bond length is 2.54 Å. The Fe(1)-Si(1) bond length is 1.01 Å. In the second Fe site, Fe(2) is bonded in a 8-coordinate geometry to four equivalent Ba(1), one Fe(1), two equivalent Fe(2), and one Si(1) atom. Both Fe(2)-Fe(2) bond lengths are 2.99 Å. The Fe(2)-Si(1) bond length is 2.76 Å. Si(1) is bonded in a single-bond geometry to one Fe(1) and one Fe(2) atom.