data_SrCr4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.97
_cell_length_b   5.97
_cell_length_c   5.97
_cell_angle_alpha   109.47
_cell_angle_beta   109.47
_cell_angle_gamma   109.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrCr4
_chemical_formula_sum   'Sr1 Cr4'
_cell_volume   163.99
_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
  Sr  Sr4  1  0.0  0.0  0.0  1.0
  Cr  Cr0  1  0.72  0.28  0.72  1.0
  Cr  Cr1  1  0.72  0.72  0.72  1.0
  Cr  Cr2  1  0.72  0.72  0.28  1.0
  Cr  Cr3  1  0.28  0.72  0.72  1.0

data_SrCr4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   9.75
_cell_length_b   9.75
_cell_length_c   5.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrCr4
_chemical_formula_sum   'Sr3 Cr12'
_cell_volume   491.98
_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+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
  10  '-y+2/3, -x+1/3, z+1/3'
  11  '-x+y+2/3, y+1/3, z+1/3'
  12  'x+2/3, x-y+1/3, z+1/3'
  13  'x+1/3, y+2/3, z+2/3'
  14  '-y+1/3, x-y+2/3, z+2/3'
  15  '-x+y+1/3, -x+2/3, z+2/3'
  16  '-y+1/3, -x+2/3, z+2/3'
  17  '-x+y+1/3, y+2/3, z+2/3'
  18  'x+1/3, x-y+2/3, z+2/3'
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
  Sr  Sr0  3  0.0  0.0  0.0  1.0
  Cr  Cr1  9  0.03  0.52  0.24  1.0
  Cr  Cr2  3  0.0  0.0  0.72  1.0

Sr Cr Cr Cr Cr
Sr Cr Cr Cr Cr 0 2 - - - 0 1 - - - 0 1 - o - 0 3 - - o 0 3 - - - 0 4 o - - 0 4 - - - 1 4 o - o 1 4 + o o 1 2 o o o 1 2 o - o 1 3 o o + 1 3 o - o 2 3 o o + 2 3 o o o 2 4 + o o 2 4 o o o 3 4 o o - 3 4 + o o 
SrCr4 crystallizes in the trigonal R3m space group. Sr(1) is bonded in a single-bond geometry to one Cr(2) and three equivalent Cr(1) atoms. The Sr(1)-Cr(2) bond length is 1.65 Å. All Sr(1)-Cr(1) bond lengths are 3.16 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and one Cr(2) atom. The Cr(1)-Cr(2) bond length is 2.68 Å. In the second Cr site, Cr(2) is bonded in a single-bond geometry to one Sr(1) and three equivalent Cr(1) atoms.