data_MgPt3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgPt3
_chemical_formula_sum   'Mg2 Pt6'
_cell_volume   132.25
_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  0.55  0.55  0.55  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Pt  Pt2  1  0.55  0.82  0.0  1.0
  Pt  Pt3  1  0.55  0.27  0.0  1.0
  Pt  Pt4  1  0.82  0.0  0.55  1.0
  Pt  Pt5  1  0.0  0.55  0.82  1.0
  Pt  Pt6  1  0.0  0.55  0.27  1.0
  Pt  Pt7  1  0.27  0.0  0.55  1.0

data_MgPt3
_symmetry_space_group_name_H-M   R3
_cell_length_a   7.21
_cell_length_b   7.21
_cell_length_c   8.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   MgPt3
_chemical_formula_sum   'Mg6 Pt18'
_cell_volume   396.75
_cell_formula_units_Z   6
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  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+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  0.55  1.0
  Pt  Pt2  9  0.03  0.24  0.79  1.0
  Pt  Pt3  9  0.06  0.67  0.94  1.0

Mg Mg Pt Pt Pt Pt Pt Pt
MgPt3 is beta Plutonium-derived structured and crystallizes in the trigonal R3 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to six equivalent Pt(1) and six equivalent Pt(2) atoms to form distorted edge-sharing MgPt12 cuboctahedra. There are three shorter (2.69 Å) and three longer (3.12 Å) Mg(1)-Pt(1) bond lengths. There are three shorter (2.69 Å) and three longer (3.12 Å) Mg(1)-Pt(2) bond lengths. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to six equivalent Pt(1) and six equivalent Pt(2) atoms. There are three shorter (2.48 Å) and three longer (2.93 Å) Mg(2)-Pt(1) bond lengths. There are three shorter (2.69 Å) and three longer (3.12 Å) Mg(2)-Pt(2) bond lengths. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and one Pt(2) atom. The Pt(1)-Pt(2) bond length is 2.31 Å. In the second Pt site, Pt(2) is bonded in a 2-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and one Pt(1) atom.