data_MgTa3Cd
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.0
_cell_length_b   5.0
_cell_length_c   5.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgTa3Cd
_chemical_formula_sum   'Mg1 Ta3 Cd1'
_cell_volume   125.14
_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
  Ta  Ta2  1  0.5  0.0  0.5  1.0
  Ta  Ta3  1  0.5  0.5  0.0  1.0
  Ta  Ta4  1  0.0  0.5  0.5  1.0
  Cd  Cd1  1  0.5  0.5  0.5  1.0

data_MgTa3Cd
_symmetry_space_group_name_H-M   Pm-3m
_cell_length_a   5.0
_cell_length_b   5.0
_cell_length_c   5.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   221
_chemical_formula_structural   MgTa3Cd
_chemical_formula_sum   'Mg1 Ta3 Cd1'
_cell_volume   125.14
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-y, x, z'
  4  'y, -x, -z'
  5  '-x, -y, z'
  6  'x, y, -z'
  7  'y, -x, z'
  8  '-y, x, -z'
  9  'x, -y, -z'
  10  '-x, y, z'
  11  '-y, -x, -z'
  12  'y, x, z'
  13  '-x, y, -z'
  14  'x, -y, z'
  15  'y, x, -z'
  16  '-y, -x, z'
  17  'z, x, y'
  18  '-z, -x, -y'
  19  'z, -y, x'
  20  '-z, y, -x'
  21  'z, -x, -y'
  22  '-z, x, y'
  23  'z, y, -x'
  24  '-z, -y, x'
  25  '-z, x, -y'
  26  'z, -x, y'
  27  '-z, -y, -x'
  28  'z, y, x'
  29  '-z, -x, y'
  30  'z, x, -y'
  31  '-z, y, x'
  32  'z, -y, -x'
  33  'y, z, x'
  34  '-y, -z, -x'
  35  'x, z, -y'
  36  '-x, -z, y'
  37  '-y, z, -x'
  38  'y, -z, x'
  39  '-x, z, y'
  40  'x, -z, -y'
  41  '-y, -z, x'
  42  'y, z, -x'
  43  '-x, -z, -y'
  44  'x, z, y'
  45  'y, -z, -x'
  46  '-y, z, x'
  47  'x, -z, y'
  48  '-x, z, -y'
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
  Ta  Ta1  3  0.0  0.5  0.5  1.0
  Cd  Cd2  1  0.5  0.5  0.5  1.0

Mg Ta Ta Ta Cd
MgTa3Cd is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded to twelve equivalent Ta(1) atoms to form MgTa12 cuboctahedra that share corners with twelve equivalent Mg(1)Ta12 cuboctahedra, faces with six equivalent Mg(1)Ta12 cuboctahedra, and faces with eight equivalent Cd(1)Ta6 octahedra. There are three shorter (3.53 Å) and nine longer (3.54 Å) Mg(1)-Ta(1) bond lengths. Ta(1) is bonded in a distorted linear geometry to four equivalent Mg(1) and two equivalent Cd(1) atoms. There is one shorter (2.50 Å) and one longer (2.51 Å) Ta(1)-Cd(1) bond length. Cd(1) is bonded to six equivalent Ta(1) atoms to form CdTa6 octahedra that share corners with six equivalent Cd(1)Ta6 octahedra and faces with eight equivalent Mg(1)Ta12 cuboctahedra. The corner-sharing octahedra are not tilted.