The compound described by ZnAs2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form ZnAs4 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the second Zn site, Zn(2) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form ZnAs4 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Zn(2), one As(2), and one As(3) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the second As site, As(2) is bonded to one Zn(1), one Zn(2), one As(1), and one As(4) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Zn(1), one Zn(2), one As(1), and one As(4) atom. In the fourth As site, As(4) is bonded to two equivalent Zn(1), one As(2), and one As(3) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. is represented by the CIF file [CIF]
data_ZnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.694
_cell_length_b   8.024
_cell_length_c   9.263
_cell_angle_alpha   102.501
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   558.344
_cell_formula_units_Z   8
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  Zn0  1  0.749  0.395  0.082  1.0
  Zn  Zn1  1  0.249  0.105  0.918  1.0
  Zn  Zn2  1  0.251  0.605  0.918  1.0
  Zn  Zn3  1  0.751  0.895  0.082  1.0
  Zn  Zn4  1  0.101  0.222  0.389  1.0
  Zn  Zn5  1  0.601  0.278  0.611  1.0
  Zn  Zn6  1  0.899  0.778  0.611  1.0
  Zn  Zn7  1  0.399  0.722  0.389  1.0
  As  As8  1  0.425  0.219  0.385  1.0
  As  As9  1  0.925  0.281  0.615  1.0
  As  As10  1  0.575  0.781  0.615  1.0
  As  As11  1  0.075  0.719  0.385  1.0
  As  As12  1  0.013  0.432  0.238  1.0
  As  As13  1  0.513  0.068  0.762  1.0
  As  As14  1  0.987  0.568  0.762  1.0
  As  As15  1  0.487  0.932  0.238  1.0
  As  As16  1  0.491  0.436  0.243  1.0
  As  As17  1  0.991  0.064  0.757  1.0
  As  As18  1  0.509  0.564  0.757  1.0
  As  As19  1  0.009  0.936  0.243  1.0
  As  As20  1  0.255  0.392  0.067  1.0
  As  As21  1  0.755  0.108  0.933  1.0
  As  As22  1  0.745  0.608  0.933  1.0
  As  As23  1  0.245  0.892  0.067  1.0
[/CIF]
.
The compound described by ZnAs2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form ZnAs4 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the second Zn site, Zn(2) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form ZnAs4 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Zn(2), one As(2), and one As(3) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the second As site, As(2) is bonded to one Zn(1), one Zn(2), one As(1), and one As(4) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Zn(1), one Zn(2), one As(1), and one As(4) atom. In the fourth As site, As(4) is bonded to two equivalent Zn(1), one As(2), and one As(3) atom to form distorted AsZn2As2 tetrahedra that share corners with two equivalent Zn(1)As4 tetrahedra, corners with two equivalent Zn(2)As4 tetrahedra, corners with two equivalent As(1)Zn2As2 tetrahedra, corners with two equivalent As(2)Zn2As2 tetrahedra, and corners with two equivalent As(4)Zn2As2 tetrahedra. is represented by the CIF file [CIF]
data_ZnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.694
_cell_length_b   8.024
_cell_length_c   9.263
_cell_angle_alpha   102.501
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   558.344
_cell_formula_units_Z   8
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  Zn0  1  0.749  0.395  0.082  1.0
  Zn  Zn1  1  0.249  0.105  0.918  1.0
  Zn  Zn2  1  0.251  0.605  0.918  1.0
  Zn  Zn3  1  0.751  0.895  0.082  1.0
  Zn  Zn4  1  0.101  0.222  0.389  1.0
  Zn  Zn5  1  0.601  0.278  0.611  1.0
  Zn  Zn6  1  0.899  0.778  0.611  1.0
  Zn  Zn7  1  0.399  0.722  0.389  1.0
  As  As8  1  0.425  0.219  0.385  1.0
  As  As9  1  0.925  0.281  0.615  1.0
  As  As10  1  0.575  0.781  0.615  1.0
  As  As11  1  0.075  0.719  0.385  1.0
  As  As12  1  0.013  0.432  0.238  1.0
  As  As13  1  0.513  0.068  0.762  1.0
  As  As14  1  0.987  0.568  0.762  1.0
  As  As15  1  0.487  0.932  0.238  1.0
  As  As16  1  0.491  0.436  0.243  1.0
  As  As17  1  0.991  0.064  0.757  1.0
  As  As18  1  0.509  0.564  0.757  1.0
  As  As19  1  0.009  0.936  0.243  1.0
  As  As20  1  0.255  0.392  0.067  1.0
  As  As21  1  0.755  0.108  0.933  1.0
  As  As22  1  0.745  0.608  0.933  1.0
  As  As23  1  0.245  0.892  0.067  1.0
[/CIF]
.