data_ZnSnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.9
_cell_length_b   4.9
_cell_length_c   4.9
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ZnSnAs2
_chemical_formula_sum   'Zn1 Sn1 As2'
_cell_volume   83.19
_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
  Zn  Zn3  1  0.0  0.0  0.0  1.0
  Sn  Sn2  1  0.2  0.2  0.2  1.0
  As  As0  1  0.73  0.73  0.73  1.0
  As  As1  1  0.46  0.46  0.46  1.0

data_ZnSnAs2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.9
_cell_length_b   4.9
_cell_length_c   12.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   ZnSnAs2
_chemical_formula_sum   'Zn3 Sn3 As6'
_cell_volume   249.56
_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
  Zn  Zn0  3  0.0  0.0  0.0  1.0
  Sn  Sn1  3  0.0  0.0  0.8  1.0
  As  As2  3  0.0  0.0  0.27  1.0
  As  As3  3  0.0  0.0  0.54  1.0

Zn Sn As As
Zn Sn As As 0 1 o - o 0 1 - o o 0 1 o o - 0 1 o o o 0 2 - - - 0 2 - - o 0 2 - o - 0 2 o - - 0 3 - o o 0 3 o - o 0 3 o o - 1 2 - - o 1 2 - o - 1 2 o - - 1 3 - o o 1 3 o - o 1 3 o o - 1 3 o o o 2 3 o o o 2 3 o o + 2 3 o + o 2 3 + o o 
ZnSnAs2 crystallizes in the trigonal R3m space group. Zn(1) is bonded in a 4-coordinate geometry to one Sn(1) and three equivalent As(1) atoms. The Zn(1)-Sn(1) bond length is 2.37 Å. All Zn(1)-As(1) bond lengths are 2.94 Å. Sn(1) is bonded in a distorted single-bond geometry to one Zn(1) and four equivalent As(2) atoms. There are three shorter (2.94 Å) and one longer (3.21 Å) Sn(1)-As(2) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Zn(1) and three equivalent As(2) atoms. All As(1)-As(2) bond lengths are 2.94 Å. In the second As site, As(2) is bonded in a 7-coordinate geometry to four equivalent Sn(1) and three equivalent As(1) atoms.