data_Mg3Pt
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.64
_cell_length_b   4.64
_cell_length_c   4.64
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg3Pt
_chemical_formula_sum   'Mg3 Pt1'
_cell_volume   70.86
_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  0.93  0.93  0.93  1.0
  Mg  Mg1  1  0.64  0.64  0.64  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Pt  Pt3  1  0.28  0.28  0.28  1.0

data_Mg3Pt
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.64
_cell_length_b   4.64
_cell_length_c   11.38
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Mg3Pt
_chemical_formula_sum   'Mg9 Pt3'
_cell_volume   212.58
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Mg  Mg1  3  0.0  0.0  0.07  1.0
  Mg  Mg2  3  0.0  0.0  0.36  1.0
  Pt  Pt3  3  0.0  0.0  0.72  1.0

Mg Mg Mg Pt
Mg Mg Mg Pt 0 2 + + + 0 1 + o o 0 1 o + o 0 1 o o + 0 3 + + o 0 3 + o + 0 3 o + + 1 3 o o + 1 3 o + o 1 3 + o o 1 2 o + + 1 2 + o + 1 2 + + o 2 3 o o - 2 3 o - o 2 3 - o o 
Mg3Pt crystallizes in the trigonal R3m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a single-bond geometry to one Mg(3) and three equivalent Pt(1) atoms. The Mg(1)-Mg(3) bond length is 0.84 Å. All Mg(1)-Pt(1) bond lengths are 2.70 Å. In the second Mg site, Mg(2) is bonded in a distorted trigonal planar geometry to three equivalent Pt(1) atoms. All Mg(2)-Pt(1) bond lengths are 2.70 Å. In the third Mg site, Mg(3) is bonded in a single-bond geometry to one Mg(1) and four equivalent Pt(1) atoms. There are three shorter (2.74 Å) and one longer (3.24 Å) Mg(3)-Pt(1) bond length. Pt(1) is bonded in a 10-coordinate geometry to three equivalent Mg(1), three equivalent Mg(2), and four equivalent Mg(3) atoms.