data_MgCuSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   5.48
_cell_angle_alpha   102.12
_cell_angle_beta   102.12
_cell_angle_gamma   40.35
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCuSi2
_chemical_formula_sum   'Mg1 Cu1 Si2'
_cell_volume   63.86
_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  Mg1  1  0.0  0.0  0.0  1.0
  Cu  Cu0  1  0.42  0.0  0.67  1.0
  Si  Si2  1  0.09  0.0  0.7  1.0
  Si  Si3  1  0.75  0.0  0.64  1.0

data_MgCuSi2
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.97
_cell_length_b   4.3
_cell_length_c   5.48
_cell_angle_alpha   102.12
_cell_angle_beta   90.0
_cell_angle_gamma   110.18
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgCuSi2
_chemical_formula_sum   'Mg1 Cu1 Si2'
_cell_volume   63.86
_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
  Si  Si1  1  0.0  0.25  0.36  1.0
  Cu  Cu2  1  0.0  0.58  0.33  1.0
  Si  Si3  1  0.0  0.91  0.3  1.0

Mg Cu Si Si
Mg Cu Si Si 0 3 - o - 0 2 o o - 1 2 o o o 1 3 o o o 2 3 - o o 