data_AcTaCr2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.68
_cell_length_b   4.68
_cell_length_c   4.68
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AcTaCr2
_chemical_formula_sum   'Ac1 Ta1 Cr2'
_cell_volume   72.61
_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
  Ac  Ac0  1  0.31  0.31  0.31  1.0
  Ta  Ta3  1  0.0  0.0  0.0  1.0
  Cr  Cr1  1  0.97  0.97  0.97  1.0
  Cr  Cr2  1  0.66  0.66  0.66  1.0

data_AcTaCr2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.68
_cell_length_b   4.68
_cell_length_c   11.47
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   AcTaCr2
_chemical_formula_sum   'Ac3 Ta3 Cr6'
_cell_volume   217.83
_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
  Ac  Ac0  3  0.0  0.0  0.69  1.0
  Ta  Ta1  3  0.0  0.0  0.0  1.0
  Cr  Cr2  3  0.0  0.0  0.03  1.0
  Cr  Cr3  3  0.0  0.0  0.34  1.0

Ac Ta Cr Cr
Ac Ta Cr Cr 0 1 o o + 0 1 o + o 0 1 + o o 0 2 - - o 0 2 - o - 0 2 o - - 0 3 - o o 0 3 o - o 0 3 o o - 1 2 - - - 1 3 o - - 1 3 - o - 1 3 - - o 2 3 + o o 2 3 o + o 2 3 o o + 
AcTaCr2 crystallizes in the trigonal R3m space group. Ac(1) is bonded in a 11-coordinate geometry to four equivalent Ta(1), three equivalent Cr(1), and four equivalent Cr(2) atoms. There are three shorter (2.72 Å) and one longer (3.57 Å) Ac(1)-Ta(1) bond length. All Ac(1)-Cr(1) bond lengths are 2.71 Å. There are three shorter (2.71 Å) and one longer (3.95 Å) Ac(1)-Cr(2) bond length. Ta(1) is bonded in a single-bond geometry to four equivalent Ac(1) and one Cr(1) atom. The Ta(1)-Cr(1) bond length is 0.38 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a single-bond geometry to three equivalent Ac(1) and one Ta(1) atom. In the second Cr site, Cr(2) is bonded in a distorted trigonal planar geometry to four equivalent Ac(1) atoms.