data_MgPt2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.09
_cell_length_b   6.09
_cell_length_c   6.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgPt2
_chemical_formula_sum   'Mg4 Pt8'
_cell_volume   226.03
_cell_formula_units_Z   4
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
  Mg  Mg1  1  0.0  0.05  0.05  1.0
  Mg  Mg2  1  0.05  0.0  0.05  1.0
  Mg  Mg3  1  0.05  0.05  0.0  1.0
  Pt  Pt4  1  0.74  0.78  0.35  1.0
  Pt  Pt5  1  0.74  0.35  0.31  1.0
  Pt  Pt6  1  0.31  0.74  0.35  1.0
  Pt  Pt7  1  0.31  0.31  0.31  1.0
  Pt  Pt8  1  0.78  0.78  0.78  1.0
  Pt  Pt9  1  0.78  0.35  0.74  1.0
  Pt  Pt10  1  0.35  0.74  0.78  1.0
  Pt  Pt11  1  0.35  0.31  0.74  1.0

data_MgPt2
_symmetry_space_group_name_H-M   R3
_cell_length_a   8.61
_cell_length_b   8.61
_cell_length_c   10.55
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   MgPt2
_chemical_formula_sum   'Mg12 Pt24'
_cell_volume   678.09
_cell_formula_units_Z   12
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  9  0.02  0.98  0.03  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Pt  Pt2  9  0.06  0.51  0.29  1.0
  Pt  Pt3  9  0.17  0.78  0.13  1.0
  Pt  Pt4  3  0.0  0.0  0.31  1.0
  Pt  Pt5  3  0.0  0.0  0.78  1.0

Mg Mg Mg Mg Pt Pt Pt Pt Pt Pt Pt Pt
MgPt2 crystallizes in the trigonal R3 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to three equivalent Mg(2), one Pt(4), and three equivalent Pt(1) atoms. All Mg(1)-Mg(2) bond lengths are 0.39 Å. The Mg(1)-Pt(4) bond length is 2.27 Å. All Mg(1)-Pt(1) bond lengths are 2.98 Å. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Mg(1), two equivalent Mg(2), one Pt(2), one Pt(3), and two equivalent Pt(1) atoms. Both Mg(2)-Mg(2) bond lengths are 0.39 Å. The Mg(2)-Pt(2) bond length is 2.93 Å. The Mg(2)-Pt(3) bond length is 2.93 Å. There is one shorter (2.93 Å) and one longer (2.95 Å) Mg(2)-Pt(1) bond length. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 6-coordinate geometry to one Mg(1), two equivalent Mg(2), one Pt(4), and two equivalent Pt(2) atoms. The Pt(1)-Pt(4) bond length is 2.64 Å. Both Pt(1)-Pt(2) bond lengths are 2.64 Å. In the second Pt site, Pt(2) is bonded in a 4-coordinate geometry to one Mg(2), one Pt(3), and two equivalent Pt(1) atoms. The Pt(2)-Pt(3) bond length is 2.64 Å. In the third Pt site, Pt(3) is bonded in a 6-coordinate geometry to three equivalent Mg(2) and three equivalent Pt(2) atoms. In the fourth Pt site, Pt(4) is bonded in a single-bond geometry to one Mg(1) and three equivalent Pt(1) atoms.