data_Y3AsC
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.82
_cell_length_b   4.82
_cell_length_c   4.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Y3AsC
_chemical_formula_sum   'Y3 As1 C1'
_cell_volume   111.81
_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
  Y  Y0  1  0.0  0.41  0.0  1.0
  Y  Y1  1  0.0  0.0  0.41  1.0
  Y  Y2  1  0.41  0.0  0.0  1.0
  As  As3  1  0.41  0.41  0.41  1.0
  C  C4  1  0.0  0.0  0.0  1.0

data_Y3AsC
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.81
_cell_length_b   6.81
_cell_length_c   8.34
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Y3AsC
_chemical_formula_sum   'Y9 As3 C3'
_cell_volume   335.43
_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
  Y  Y0  9  0.2  0.39  0.8  1.0
  As  As1  3  0.0  0.0  0.41  1.0
  C  C2  3  0.0  0.0  0.0  1.0

Y Y Y As C
Y Y Y As C 0 4 o o o 0 3 o o o 0 3 o o - 0 3 - o o 1 4 o o o 1 3 o o o 1 3 o - o 1 3 - o o 2 4 o o o 2 3 o o o 2 3 o o - 2 3 o - o 3 4 o o o 
Y3CAs crystallizes in the trigonal R3m space group. Y(1) is bonded in a distorted single-bond geometry to two equivalent C(1) and three equivalent As(1) atoms. There is one shorter (1.97 Å) and one longer (2.85 Å) Y(1)-C(1) bond length. There is one shorter (2.79 Å) and two longer (3.46 Å) Y(1)-As(1) bond lengths. C(1) is bonded to six equivalent Y(1) atoms to form distorted corner-sharing CY6 octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded in a 9-coordinate geometry to nine equivalent Y(1) atoms.