The crystal structure described by CrZnAs2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted CrO5 square pyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and edges with two equivalent Zn(1)O6 octahedra. Zn(1) is bonded to one O(1), one O(5), one O(6), one O(7), and two equivalent O(3) atoms to form distorted ZnO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Zn(1)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with three equivalent Zn(1)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, and  a cornercorner with one As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-54°. In the second As site, As(2) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with three equivalent Zn(1)O6 octahedra, corners with three equivalent Cr(1)O5 square pyramids, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-50°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one As(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one As(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one As(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_ZnCrAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.656
_cell_length_b   7.360
_cell_length_c   9.794
_cell_angle_alpha   67.120
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   574.841
_cell_formula_units_Z   4
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  0.070  0.730  0.896  1.0
  Zn  Zn1  1  0.570  0.270  0.604  1.0
  Zn  Zn2  1  0.930  0.270  0.104  1.0
  Zn  Zn3  1  0.430  0.730  0.396  1.0
  Cr  Cr4  1  0.944  0.201  0.667  1.0
  Cr  Cr5  1  0.444  0.799  0.833  1.0
  Cr  Cr6  1  0.056  0.799  0.333  1.0
  Cr  Cr7  1  0.556  0.201  0.167  1.0
  As  As8  1  0.774  0.565  0.749  1.0
  As  As9  1  0.274  0.435  0.751  1.0
  As  As10  1  0.226  0.435  0.251  1.0
  As  As11  1  0.726  0.565  0.249  1.0
  As  As12  1  0.728  0.969  0.963  1.0
  As  As13  1  0.228  0.031  0.537  1.0
  As  As14  1  0.272  0.031  0.037  1.0
  As  As15  1  0.772  0.969  0.463  1.0
  O  O16  1  0.735  0.135  0.047  1.0
  O  O17  1  0.235  0.865  0.453  1.0
  O  O18  1  0.265  0.865  0.953  1.0
  O  O19  1  0.765  0.135  0.547  1.0
  O  O20  1  0.597  0.643  0.766  1.0
  O  O21  1  0.097  0.357  0.734  1.0
  O  O22  1  0.403  0.357  0.234  1.0
  O  O23  1  0.903  0.643  0.266  1.0
  O  O24  1  0.899  0.534  0.893  1.0
  O  O25  1  0.399  0.466  0.607  1.0
  O  O26  1  0.101  0.466  0.107  1.0
  O  O27  1  0.601  0.534  0.393  1.0
  O  O28  1  0.861  0.746  0.588  1.0
  O  O29  1  0.361  0.254  0.912  1.0
  O  O30  1  0.139  0.254  0.412  1.0
  O  O31  1  0.639  0.746  0.088  1.0
  O  O32  1  0.913  0.023  0.330  1.0
  O  O33  1  0.413  0.977  0.170  1.0
  O  O34  1  0.087  0.977  0.670  1.0
  O  O35  1  0.587  0.023  0.830  1.0
  O  O36  1  0.736  0.364  0.201  1.0
  O  O37  1  0.236  0.636  0.299  1.0
  O  O38  1  0.264  0.636  0.799  1.0
  O  O39  1  0.764  0.364  0.701  1.0
  O  O40  1  0.597  0.937  0.400  1.0
  O  O41  1  0.097  0.063  0.100  1.0
  O  O42  1  0.403  0.063  0.600  1.0
  O  O43  1  0.903  0.937  0.900  1.0
[/CIF]
.
The crystal structure described by CrZnAs2O7 crystallizes in the monoclinic P2_1/c space group. Cr(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted CrO5 square pyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and edges with two equivalent Zn(1)O6 octahedra. Zn(1) is bonded to one O(1), one O(5), one O(6), one O(7), and two equivalent O(3) atoms to form distorted ZnO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Zn(1)O6 octahedra, and edges with two equivalent Cr(1)O5 square pyramids. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with three equivalent Zn(1)O6 octahedra, corners with two equivalent Cr(1)O5 square pyramids, and  a cornercorner with one As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-54°. In the second As site, As(2) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with three equivalent Zn(1)O6 octahedra, corners with three equivalent Cr(1)O5 square pyramids, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-50°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Cr(1), one Zn(1), and one As(2) atom. In the fourth O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(1), one Zn(1), and one As(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Cr(1) and one As(1) atom. In the sixth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one As(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_ZnCrAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.656
_cell_length_b   7.360
_cell_length_c   9.794
_cell_angle_alpha   67.120
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   574.841
_cell_formula_units_Z   4
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  0.070  0.730  0.896  1.0
  Zn  Zn1  1  0.570  0.270  0.604  1.0
  Zn  Zn2  1  0.930  0.270  0.104  1.0
  Zn  Zn3  1  0.430  0.730  0.396  1.0
  Cr  Cr4  1  0.944  0.201  0.667  1.0
  Cr  Cr5  1  0.444  0.799  0.833  1.0
  Cr  Cr6  1  0.056  0.799  0.333  1.0
  Cr  Cr7  1  0.556  0.201  0.167  1.0
  As  As8  1  0.774  0.565  0.749  1.0
  As  As9  1  0.274  0.435  0.751  1.0
  As  As10  1  0.226  0.435  0.251  1.0
  As  As11  1  0.726  0.565  0.249  1.0
  As  As12  1  0.728  0.969  0.963  1.0
  As  As13  1  0.228  0.031  0.537  1.0
  As  As14  1  0.272  0.031  0.037  1.0
  As  As15  1  0.772  0.969  0.463  1.0
  O  O16  1  0.735  0.135  0.047  1.0
  O  O17  1  0.235  0.865  0.453  1.0
  O  O18  1  0.265  0.865  0.953  1.0
  O  O19  1  0.765  0.135  0.547  1.0
  O  O20  1  0.597  0.643  0.766  1.0
  O  O21  1  0.097  0.357  0.734  1.0
  O  O22  1  0.403  0.357  0.234  1.0
  O  O23  1  0.903  0.643  0.266  1.0
  O  O24  1  0.899  0.534  0.893  1.0
  O  O25  1  0.399  0.466  0.607  1.0
  O  O26  1  0.101  0.466  0.107  1.0
  O  O27  1  0.601  0.534  0.393  1.0
  O  O28  1  0.861  0.746  0.588  1.0
  O  O29  1  0.361  0.254  0.912  1.0
  O  O30  1  0.139  0.254  0.412  1.0
  O  O31  1  0.639  0.746  0.088  1.0
  O  O32  1  0.913  0.023  0.330  1.0
  O  O33  1  0.413  0.977  0.170  1.0
  O  O34  1  0.087  0.977  0.670  1.0
  O  O35  1  0.587  0.023  0.830  1.0
  O  O36  1  0.736  0.364  0.201  1.0
  O  O37  1  0.236  0.636  0.299  1.0
  O  O38  1  0.264  0.636  0.799  1.0
  O  O39  1  0.764  0.364  0.701  1.0
  O  O40  1  0.597  0.937  0.400  1.0
  O  O41  1  0.097  0.063  0.100  1.0
  O  O42  1  0.403  0.063  0.600  1.0
  O  O43  1  0.903  0.937  0.900  1.0
[/CIF]
.