data_Mg2FeAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   135.14
_cell_angle_beta   135.14
_cell_angle_gamma   65.31
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2FeAs
_chemical_formula_sum   'Mg2 Fe1 As1'
_cell_volume   66.99
_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
  Mg  Mg2  1  0.0  0.97  0.17  1.0
  Mg  Mg3  1  0.0  0.0  0.0  1.0
  Fe  Fe1  1  0.0  0.0  0.34  1.0
  As  As0  1  0.97  0.0  0.17  1.0

data_Mg2FeAs
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.93
_cell_length_b   3.93
_cell_length_c   5.15
_cell_angle_alpha   112.43
_cell_angle_beta   112.43
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2FeAs
_chemical_formula_sum   'Mg2 Fe1 As1'
_cell_volume   66.99
_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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Mg  Mg1  1  0.8  0.97  0.8  1.0
  Fe  Fe2  1  0.66  0.0  0.66  1.0
  As  As3  1  0.83  0.0  0.8  1.0

Mg Mg Fe As