data_Na2FePt
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.66
_cell_length_b   2.66
_cell_length_c   9.57
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2FePt
_chemical_formula_sum   'Na2 Fe1 Pt1'
_cell_volume   67.67
_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
  Na  Na1  1  0.33  0.33  0.44  1.0
  Na  Na2  1  0.33  0.33  0.13  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Pt  Pt3  1  0.0  0.0  0.79  1.0

data_Na2FePt
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.76
_cell_length_b   3.76
_cell_length_c   9.57
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2FePt
_chemical_formula_sum   'Na4 Fe2 Pt2'
_cell_volume   135.35
_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
  Na  Na0  2  0.33  0.0  0.13  1.0
  Na  Na1  2  0.33  0.0  0.44  1.0
  Fe  Fe2  2  0.0  0.0  0.0  1.0
  Pt  Pt3  2  0.0  0.0  0.79  1.0

Na Na Fe Pt
Na2FePt crystallizes in the monoclinic Cm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one Na(2), four equivalent Na(1), and one Pt(1) atom to form a mixture of distorted edge and corner-sharing NaNa5Pt octahedra. The corner-sharing octahedra are not tilted. The Na(1)-Na(2) bond length is 2.98 Å. All Na(1)-Na(1) bond lengths are 2.66 Å. The Na(1)-Pt(1) bond length is 3.52 Å. In the second Na site, Na(2) is bonded in a distorted single-bond geometry to one Na(1) and three equivalent Fe(1) atoms. There is one shorter (1.77 Å) and two longer (2.35 Å) Na(2)-Fe(1) bond lengths. Fe(1) is bonded in a 4-coordinate geometry to three equivalent Na(2) and one Pt(1) atom. The Fe(1)-Pt(1) bond length is 2.04 Å. Pt(1) is bonded in a single-bond geometry to one Na(1) and one Fe(1) atom.