data_Na4SrCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.46
_cell_length_b   6.46
_cell_length_c   6.46
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na4SrCu
_chemical_formula_sum   'Na4 Sr1 Cu1'
_cell_volume   190.6
_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  Na1  1  0.72  0.72  0.41  1.0
  Na  Na2  1  0.72  0.41  0.72  1.0
  Na  Na3  1  0.41  0.72  0.72  1.0
  Na  Na4  1  0.41  0.41  0.41  1.0
  Sr  Sr5  1  0.85  0.85  0.85  1.0
  Cu  Cu0  1  0.0  0.0  0.0  1.0

data_Na4SrCu
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.46
_cell_length_b   6.46
_cell_length_c   15.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na4SrCu
_chemical_formula_sum   'Na12 Sr3 Cu3'
_cell_volume   571.8
_cell_formula_units_Z   3
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  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+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
  Na  Na0  9  0.21  0.1  0.38  1.0
  Na  Na1  3  0.0  0.0  0.59  1.0
  Sr  Sr2  3  0.0  0.0  0.15  1.0
  Cu  Cu3  3  0.0  0.0  0.0  1.0

Na Na Na Na Sr Cu
Na Na Na Na Sr Cu 0 1 o o o 0 2 o o o 0 3 + o o 0 3 o + o 0 3 o o o 0 5 + + o 1 2 o o o 1 3 + o o 1 3 o o + 1 3 o o o 1 5 + o + 2 3 o + o 2 3 o o + 2 3 o o o 2 5 o + + 3 5 o o + 3 5 o + o 3 5 + o o 3 4 - o o 3 4 o - o 3 4 o o - 4 5 + + + 
Na4SrCu crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 1-coordinate geometry to three equivalent Na(2) and one Cu(1) atom. There is one shorter (3.51 Å) and two longer (3.84 Å) Na(1)-Na(2) bond lengths. The Na(1)-Cu(1) bond length is 2.66 Å. In the second Na site, Na(2) is bonded in a 12-coordinate geometry to nine equivalent Na(1) and three equivalent Sr(1) atoms. All Na(2)-Sr(1) bond lengths are 4.10 Å. Sr(1) is bonded in a single-bond geometry to three equivalent Na(2) and one Cu(1) atom. The Sr(1)-Cu(1) bond length is 2.35 Å. Cu(1) is bonded in a distorted tetrahedral geometry to three equivalent Na(1) and one Sr(1) atom.