The structure described by U3As4 crystallizes in the trigonal R3c space group. U(1) is bonded to two equivalent As(2) and six equivalent As(1) atoms to form a mixture of distorted edge, face, and corner-sharing UAs8 hexagonal bipyramids. There are two inequivalent As sites. In the first As site, As(1) is bonded to six equivalent U(1) atoms to form a mixture of distorted edge, face, and corner-sharing AsU6 octahedra. The corner-sharing octahedral tilt angles range from 15-51°. In the second As site, As(2) is bonded to six equivalent U(1) atoms to form a mixture of distorted edge, face, and corner-sharing AsU6 octahedra. The corner-sharing octahedral tilt angles range from 15-51°. is represented by the CIF file [CIF]
data_U3As4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.450
_cell_length_b   7.449
_cell_length_c   7.434
_cell_angle_alpha   109.427
_cell_angle_beta   109.431
_cell_angle_gamma   109.515
_symmetry_Int_Tables_number   1
_cell_volume   317.783
_cell_formula_units_Z   2
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
  U  U0  1  0.749  0.875  0.125  1.0
  U  U1  1  0.625  0.375  0.250  1.0
  U  U2  1  0.875  0.125  0.750  1.0
  U  U3  1  0.125  0.751  0.875  1.0
  U  U4  1  0.375  0.249  0.625  1.0
  U  U5  1  0.251  0.625  0.375  1.0
  As  As6  1  0.659  0.659  0.659  1.0
  As  As7  1  0.341  0.500  1.000  1.0
  As  As8  1  0.500  0.000  0.342  1.0
  As  As9  1  0.000  0.341  0.500  1.0
  As  As10  1  0.500  0.000  0.842  1.0
  As  As11  1  1.000  0.841  0.500  1.0
  As  As12  1  0.159  0.159  0.159  1.0
  As  As13  1  0.841  0.500  1.000  1.0
[/CIF]
.
The structure described by U3As4 crystallizes in the trigonal R3c space group. U(1) is bonded to two equivalent As(2) and six equivalent As(1) atoms to form a mixture of distorted edge, face, and corner-sharing UAs8 hexagonal bipyramids. There are two inequivalent As sites. In the first As site, As(1) is bonded to six equivalent U(1) atoms to form a mixture of distorted edge, face, and corner-sharing AsU6 octahedra. The corner-sharing octahedral tilt angles range from 15-51°. In the second As site, As(2) is bonded to six equivalent U(1) atoms to form a mixture of distorted edge, face, and corner-sharing AsU6 octahedra. The corner-sharing octahedral tilt angles range from 15-51°. is represented by the CIF file [CIF]
data_U3As4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.450
_cell_length_b   7.449
_cell_length_c   7.434
_cell_angle_alpha   109.427
_cell_angle_beta   109.431
_cell_angle_gamma   109.515
_symmetry_Int_Tables_number   1
_cell_volume   317.783
_cell_formula_units_Z   2
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
  U  U0  1  0.749  0.875  0.125  1.0
  U  U1  1  0.625  0.375  0.250  1.0
  U  U2  1  0.875  0.125  0.750  1.0
  U  U3  1  0.125  0.751  0.875  1.0
  U  U4  1  0.375  0.249  0.625  1.0
  U  U5  1  0.251  0.625  0.375  1.0
  As  As6  1  0.659  0.659  0.659  1.0
  As  As7  1  0.341  0.500  1.000  1.0
  As  As8  1  0.500  0.000  0.342  1.0
  As  As9  1  0.000  0.341  0.500  1.0
  As  As10  1  0.500  0.000  0.842  1.0
  As  As11  1  1.000  0.841  0.500  1.0
  As  As12  1  0.159  0.159  0.159  1.0
  As  As13  1  0.841  0.500  1.000  1.0
[/CIF]
.