data_MgP
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.55
_cell_length_b   5.55
_cell_length_c   4.54
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   149.69
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgP
_chemical_formula_sum   'Mg2 P2'
_cell_volume   70.51
_cell_formula_units_Z   2
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  0.45  0.72  0.4  1.0
  Mg  Mg1  1  0.45  0.28  0.13  1.0
  P  P2  1  0.45  0.99  0.4  1.0
  P  P3  1  0.45  0.01  0.13  1.0

data_MgP
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.9
_cell_length_b   4.54
_cell_length_c   5.55
_cell_angle_alpha   90.0
_cell_angle_beta   105.15
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   MgP
_chemical_formula_sum   'Mg2 P2'
_cell_volume   70.51
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.28  0.63  0.78  1.0
  P  P1  2  0.01  0.63  0.51  1.0

Mg Mg P P