data_MgNbSi2
_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   137.03
_cell_angle_beta   137.03
_cell_angle_gamma   62.39
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNbSi2
_chemical_formula_sum   'Mg1 Nb1 Si2'
_cell_volume   62.59
_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
  Nb  Nb1  1  0.89  0.0  0.2  1.0
  Si  Si2  1  0.0  0.0  0.4  1.0
  Si  Si3  1  0.0  0.89  0.2  1.0

data_MgNbSi2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.77
_cell_length_b   3.77
_cell_length_c   5.15
_cell_angle_alpha   111.48
_cell_angle_beta   111.48
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNbSi2
_chemical_formula_sum   'Mg1 Nb1 Si2'
_cell_volume   62.59
_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
  Nb  Nb1  1  0.2  0.32  0.32  1.0
  Si  Si2  1  0.32  0.2  0.32  1.0
  Si  Si3  1  0.4  0.4  0.4  1.0

Mg Nb Si Si
Mg Nb Si Si 0 1 - o o 0 3 o - o 1 3 + - o 1 2 + o o 2 3 o - o 