data_CaFe4As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.99
_cell_length_b   4.99
_cell_length_c   4.99
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaFe4As
_chemical_formula_sum   'Ca1 Fe4 As1'
_cell_volume   87.86
_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
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Fe  Fe2  1  0.41  0.41  0.65  1.0
  Fe  Fe3  1  0.41  0.65  0.41  1.0
  Fe  Fe4  1  0.65  0.41  0.41  1.0
  Fe  Fe5  1  0.65  0.65  0.65  1.0
  As  As0  1  0.29  0.29  0.29  1.0

data_CaFe4As
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.99
_cell_length_b   4.99
_cell_length_c   12.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaFe4As
_chemical_formula_sum   'Ca3 Fe12 As3'
_cell_volume   263.59
_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
  Ca  Ca0  3  0.0  0.0  0.0  1.0
  Fe  Fe1  9  0.08  0.16  0.51  1.0
  Fe  Fe2  3  0.0  0.0  0.35  1.0
  As  As3  3  0.0  0.0  0.71  1.0

Ca Fe Fe Fe Fe As
CaFe4As crystallizes in the trigonal R3m space group. Ca(1) is bonded in a 9-coordinate geometry to three equivalent Fe(1), three equivalent Fe(2), and three equivalent As(1) atoms. All Ca(1)-Fe(1) bond lengths are 2.90 Å. All Ca(1)-Fe(2) bond lengths are 2.89 Å. All Ca(1)-As(1) bond lengths are 2.92 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to one Ca(1), one Fe(2), two equivalent Fe(1), and two equivalent As(1) atoms. The Fe(1)-Fe(2) bond length is 2.07 Å. Both Fe(1)-Fe(1) bond lengths are 1.19 Å. There is one shorter (2.49 Å) and one longer (2.76 Å) Fe(1)-As(1) bond length. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Fe(1), and three equivalent As(1) atoms. All Fe(2)-As(1) bond lengths are 2.89 Å. As(1) is bonded in a 12-coordinate geometry to three equivalent Ca(1), three equivalent Fe(2), and six equivalent Fe(1) atoms.