data_Na4TiCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.99
_cell_length_b   5.99
_cell_length_c   5.99
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na4TiCr
_chemical_formula_sum   'Na4 Ti1 Cr1'
_cell_volume   151.6
_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  0.18  0.18  0.29  1.0
  Na  Na2  1  0.18  0.29  0.18  1.0
  Na  Na3  1  0.29  0.18  0.18  1.0
  Na  Na4  1  0.29  0.29  0.29  1.0
  Ti  Ti5  1  0.0  0.0  0.0  1.0
  Cr  Cr0  1  0.12  0.12  0.12  1.0

data_Na4TiCr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.99
_cell_length_b   5.99
_cell_length_c   14.66
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na4TiCr
_chemical_formula_sum   'Na12 Ti3 Cr3'
_cell_volume   454.81
_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  0.04  0.07  0.79  1.0
  Na  Na1  3  0.0  0.0  0.71  1.0
  Ti  Ti2  3  0.0  0.0  0.0  1.0
  Cr  Cr3  3  0.0  0.0  0.88  1.0

Na Na Na Na Ti Cr
Na Na Na Na Ti Cr 0 2 o o o 0 1 o o o 0 3 o o o 0 5 o o o 1 2 o o o 1 3 o o o 1 5 o o o 2 3 o o o 2 5 o o o 4 5 o o o 
Na4TiCr crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one Ti(1), and one Cr(1) atom. The Na(1)-Na(2) bond length is 1.16 Å. Both Na(1)-Na(1) bond lengths are 0.67 Å. The Na(1)-Ti(1) bond length is 3.54 Å. The Na(1)-Cr(1) bond length is 1.48 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent Na(1) and three equivalent Ti(1) atoms. All Na(2)-Ti(1) bond lengths are 3.52 Å. Ti(1) is bonded in a distorted single-bond geometry to three equivalent Na(1), three equivalent Na(2), and one Cr(1) atom. The Ti(1)-Cr(1) bond length is 1.70 Å. Cr(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Na(1) and one Ti(1) atom.