The material described by Ba3Zn2As4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to three equivalent Zn(1), three equivalent As(1), and four equivalent As(2) atoms. In the second Ba site, Ba(2) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form BaAs6 octahedra that share corners with two equivalent Zn(1)Ba3As4 tetrahedra, edges with two equivalent Ba(2)As6 octahedra, and edges with four equivalent Zn(1)Ba3As4 tetrahedra. Zn(1) is bonded to three equivalent Ba(1), one As(2), and three equivalent As(1) atoms to form distorted ZnBa3As4 tetrahedra that share  a cornercorner with one Ba(2)As6 octahedra, edges with two equivalent Ba(2)As6 octahedra, edges with two equivalent Zn(1)Ba3As4 tetrahedra, and faces with two equivalent Zn(1)Ba3As4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 7-coordinate geometry to one Ba(2), three equivalent Ba(1), and three equivalent Zn(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Ba(2), four equivalent Ba(1), one Zn(1), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3(ZnAs2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.800
_cell_length_b   8.800
_cell_length_c   7.279
_cell_angle_alpha   67.555
_cell_angle_beta   67.555
_cell_angle_gamma   29.613
_symmetry_Int_Tables_number   1
_cell_volume   255.914
_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
  Ba  Ba0  1  0.144  0.144  0.416  1.0
  Ba  Ba1  1  0.856  0.856  0.584  1.0
  Ba  Ba2  1  0.000  0.000  0.000  1.0
  Zn  Zn3  1  0.329  0.329  0.961  1.0
  Zn  Zn4  1  0.671  0.671  0.039  1.0
  As  As5  1  0.206  0.206  0.839  1.0
  As  As6  1  0.794  0.794  0.161  1.0
  As  As7  1  0.488  0.488  0.680  1.0
  As  As8  1  0.512  0.512  0.320  1.0
[/CIF]
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The material described by Ba3Zn2As4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to three equivalent Zn(1), three equivalent As(1), and four equivalent As(2) atoms. In the second Ba site, Ba(2) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form BaAs6 octahedra that share corners with two equivalent Zn(1)Ba3As4 tetrahedra, edges with two equivalent Ba(2)As6 octahedra, and edges with four equivalent Zn(1)Ba3As4 tetrahedra. Zn(1) is bonded to three equivalent Ba(1), one As(2), and three equivalent As(1) atoms to form distorted ZnBa3As4 tetrahedra that share  a cornercorner with one Ba(2)As6 octahedra, edges with two equivalent Ba(2)As6 octahedra, edges with two equivalent Zn(1)Ba3As4 tetrahedra, and faces with two equivalent Zn(1)Ba3As4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 7-coordinate geometry to one Ba(2), three equivalent Ba(1), and three equivalent Zn(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Ba(2), four equivalent Ba(1), one Zn(1), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3(ZnAs2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.800
_cell_length_b   8.800
_cell_length_c   7.279
_cell_angle_alpha   67.555
_cell_angle_beta   67.555
_cell_angle_gamma   29.613
_symmetry_Int_Tables_number   1
_cell_volume   255.914
_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
  Ba  Ba0  1  0.144  0.144  0.416  1.0
  Ba  Ba1  1  0.856  0.856  0.584  1.0
  Ba  Ba2  1  0.000  0.000  0.000  1.0
  Zn  Zn3  1  0.329  0.329  0.961  1.0
  Zn  Zn4  1  0.671  0.671  0.039  1.0
  As  As5  1  0.206  0.206  0.839  1.0
  As  As6  1  0.794  0.794  0.161  1.0
  As  As7  1  0.488  0.488  0.680  1.0
  As  As8  1  0.512  0.512  0.320  1.0
[/CIF]
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