data_NaCu2Sb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.89
_cell_length_b   9.89
_cell_length_c   9.89
_cell_angle_alpha   17.94
_cell_angle_beta   17.94
_cell_angle_gamma   17.94
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCu2Sb
_chemical_formula_sum   'Na1 Cu2 Sb1'
_cell_volume   80.09
_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  0.0  0.0  0.0  1.0
  Cu  Cu0  1  0.0  0.0  0.9  1.0
  Cu  Cu1  1  0.0  0.0  0.28  1.0
  Sb  Sb3  1  0.0  0.0  0.59  1.0

data_NaCu2Sb
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.34
_cell_length_b   3.08
_cell_length_c   9.89
_cell_angle_alpha   90.0
_cell_angle_beta   100.37
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaCu2Sb
_chemical_formula_sum   'Na2 Cu4 Sb2'
_cell_volume   160.19
_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  2  0.0  0.0  0.0  1.0
  Cu  Cu1  2  -0.0  0.0  0.72  1.0
  Cu  Cu2  2  0.0  0.0  0.1  1.0
  Sb  Sb3  2  0.0  0.0  0.41  1.0

Na Cu Cu Sb
Na Cu Cu Sb 0 1 o o - 0 2 o o o 1 3 o o o 2 2 o + - 2 2 + - o 2 2 + o - 2 3 o o o 3 3 o + - 3 3 + - o 3 3 + o - 
NaCu2Sb crystallizes in the monoclinic Cm space group. Na(1) is bonded in a single-bond geometry to one Cu(1) and one Cu(2) atom. The Na(1)-Cu(1) bond length is 0.98 Å. The Na(1)-Cu(2) bond length is 2.74 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a single-bond geometry to one Na(1) and one Sb(1) atom. The Cu(1)-Sb(1) bond length is 3.08 Å. In the second Cu site, Cu(2) is bonded in a distorted single-bond geometry to one Na(1) and one Sb(1) atom. The Cu(2)-Sb(1) bond length is 3.08 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one Cu(1); one Cu(2); and six Sb(1,1) atoms to form a mixture of distorted edge and corner-sharing SbCu2Sb6 hexagonal bipyramids. All Sb(1)-Sb(1,1) bond lengths are 3.08 Å. In the second Sb site, Sb(1) is bonded to one Cu(1); one Cu(2); and six Sb(1,1) atoms to form a mixture of distorted edge and corner-sharing SbCu2Sb6 hexagonal bipyramids. The Sb(1)-Cu(1) bond length is 3.08 Å. The Sb(1)-Cu(2) bond length is 3.08 Å. Both Sb(1)-Sb(1) bond lengths are 3.08 Å.