data_SrZnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrZnAs2
_chemical_formula_sum   'Sr1 Zn1 As2'
_cell_volume   93.2
_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
  Sr  Sr2  1  0.8  0.8  0.8  1.0
  Zn  Zn3  1  0.0  0.0  0.0  1.0
  As  As0  1  0.4  0.4  0.4  1.0
  As  As1  1  0.6  0.6  0.6  1.0

data_SrZnAs2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   12.47
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrZnAs2
_chemical_formula_sum   'Sr3 Zn3 As6'
_cell_volume   279.59
_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
  Sr  Sr0  3  0.0  0.0  0.2  1.0
  Zn  Zn1  3  0.0  0.0  1.0  1.0
  As  As2  3  0.0  0.0  0.4  1.0
  As  As3  3  0.0  0.0  0.6  1.0

Sr Zn As As
SrZnAs2 crystallizes in the trigonal R3m space group. Sr(1) is bonded in a 2-coordinate geometry to one Zn(1), one As(2), and three equivalent As(1) atoms. The Sr(1)-Zn(1) bond length is 2.50 Å. The Sr(1)-As(2) bond length is 2.50 Å. All Sr(1)-As(1) bond lengths are 3.06 Å. Zn(1) is bonded in a distorted single-bond geometry to one Sr(1) and three equivalent As(1) atoms. All Zn(1)-As(1) bond lengths are 3.05 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to three equivalent Sr(1), three equivalent Zn(1), and one As(2) atom to form distorted edge-sharing AsSr3Zn3As hexagonal pyramids. The As(1)-As(2) bond length is 2.50 Å. In the second As site, As(2) is bonded in a distorted single-bond geometry to one Sr(1) and one As(1) atom.