data_TbCr2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.47
_cell_length_b   4.47
_cell_length_c   4.47
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TbCr2As
_chemical_formula_sum   'Tb1 Cr2 As1'
_cell_volume   63.33
_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
  Tb  Tb3  1  0.16  0.16  0.16  1.0
  Cr  Cr1  1  0.75  0.75  0.75  1.0
  Cr  Cr2  1  0.58  0.58  0.58  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_TbCr2As
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.47
_cell_length_b   4.47
_cell_length_c   10.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TbCr2As
_chemical_formula_sum   'Tb3 Cr6 As3'
_cell_volume   189.99
_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
  Tb  Tb0  3  0.0  0.0  0.84  1.0
  Cr  Cr1  3  0.0  0.0  0.25  1.0
  Cr  Cr2  3  0.0  0.0  0.42  1.0
  As  As3  3  0.0  0.0  0.0  1.0

Tb Cr Cr As
Tb Cr Cr As 0 3 o o o 1 2 o o o 
TbCr2As crystallizes in the trigonal R3m space group. Tb(1) is bonded in a single-bond geometry to three equivalent Cr(1), three equivalent Cr(2), and one As(1) atom. All Tb(1)-Cr(1) bond lengths are 2.75 Å. All Tb(1)-Cr(2) bond lengths are 2.75 Å. The Tb(1)-As(1) bond length is 1.79 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 8-coordinate geometry to three equivalent Tb(1), one Cr(2), and four equivalent As(1) atoms. The Cr(1)-Cr(2) bond length is 1.79 Å. There are three shorter (2.72 Å) and one longer (2.79 Å) Cr(1)-As(1) bond length. In the second Cr site, Cr(2) is bonded in a 7-coordinate geometry to three equivalent Tb(1), one Cr(1), and three equivalent As(1) atoms. All Cr(2)-As(1) bond lengths are 2.75 Å. As(1) is bonded in a single-bond geometry to one Tb(1), three equivalent Cr(2), and four equivalent Cr(1) atoms.