data_Mg3Mo
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.99
_cell_length_b   2.99
_cell_length_c   9.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg3Mo
_chemical_formula_sum   'Mg3 Mo1'
_cell_volume   77.05
_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  1.0  0.73  0.33  1.0
  Mg  Mg1  1  1.0  0.73  0.63  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Mo  Mo3  1  0.0  0.0  0.98  1.0

data_Mg3Mo
_symmetry_space_group_name_H-M   Cm
_cell_length_a   2.99
_cell_length_b   5.18
_cell_length_c   9.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg3Mo
_chemical_formula_sum   'Mg6 Mo2'
_cell_volume   154.11
_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
  Mg  Mg0  2  0.0  0.0  0.0  1.0
  Mg  Mg1  2  0.23  0.5  0.33  1.0
  Mg  Mg2  2  0.23  0.5  0.63  1.0
  Mo  Mo3  2  0.0  0.0  0.98  1.0

Mg Mg Mg Mo
Mg Mg Mg Mo 0 0 + + o 0 0 o + o 0 0 + o o 0 2 + + o 0 1 o o o 1 1 + + o 1 1 o + o 1 1 + o o 2 3 o o - 
Mg3Mo crystallizes in the monoclinic Cm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Mg(2), one Mg(3), and six equivalent Mg(1) atoms to form distorted MgMg8 hexagonal bipyramids that share corners with six equivalent Mg(1)Mg8 hexagonal bipyramids, edges with six equivalent Mg(2)Mg7Mo hexagonal bipyramids, and edges with twelve equivalent Mg(1)Mg8 hexagonal bipyramids. The Mg(1)-Mg(2) bond length is 2.92 Å. The Mg(1)-Mg(3) bond length is 3.43 Å. All Mg(1)-Mg(1) bond lengths are 2.99 Å. In the second Mg site, Mg(2) is bonded to one Mg(1), six equivalent Mg(2), and one Mo(1) atom to form MgMg7Mo hexagonal bipyramids that share corners with six equivalent Mg(2)Mg7Mo hexagonal bipyramids, edges with six equivalent Mg(1)Mg8 hexagonal bipyramids, and edges with twelve equivalent Mg(2)Mg7Mo hexagonal bipyramids. All Mg(2)-Mg(2) bond lengths are 2.99 Å. The Mg(2)-Mo(1) bond length is 3.61 Å. In the third Mg site, Mg(3) is bonded in a single-bond geometry to one Mg(1) and one Mo(1) atom. The Mg(3)-Mo(1) bond length is 0.19 Å. Mo(1) is bonded in a single-bond geometry to one Mg(2) and one Mg(3) atom.