data_Na2CaCd
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.45
_cell_length_b   6.45
_cell_length_c   6.45
_cell_angle_alpha   137.01
_cell_angle_beta   137.01
_cell_angle_gamma   62.43
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2CaCd
_chemical_formula_sum   'Na2 Ca1 Cd1'
_cell_volume   123.15
_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
  Na  Na2  1  0.36  0.0  0.76  1.0
  Na  Na3  1  0.0  0.36  0.76  1.0
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Cd  Cd1  1  0.0  0.0  0.51  1.0

data_Na2CaCd
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.68
_cell_length_b   6.68
_cell_length_c   6.45
_cell_angle_alpha   90.0
_cell_angle_beta   121.21
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2CaCd
_chemical_formula_sum   'Na4 Ca2 Cd2'
_cell_volume   246.3
_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
  Na  Na0  4  0.42  0.18  0.61  1.0
  Ca  Ca1  2  0.0  0.0  0.0  1.0
  Cd  Cd2  2  0.49  0.0  0.49  1.0

Na Na Ca Cd
Na Na Ca Cd 0 3 o o o 0 2 + o + 0 2 o o + 0 2 o o o 1 3 o o o 1 2 o o + 1 2 o o o 1 2 o + + 2 3 o o - 2 3 o o o 
Na2CaCd crystallizes in the monoclinic Cm space group. Na(1) is bonded in a single-bond geometry to one Ca(1) and one Cd(1) atom. The Na(1)-Ca(1) bond length is 3.15 Å. The Na(1)-Cd(1) bond length is 1.60 Å. Ca(1) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Cd(1) atoms. There is one shorter (3.13 Å) and one longer (3.32 Å) Ca(1)-Cd(1) bond length. Cd(1) is bonded in a distorted water-like geometry to two equivalent Na(1) and two equivalent Ca(1) atoms.