The material described by Ag2As2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 2-coordinate geometry to one O(3), one O(7), and two equivalent O(6) atoms. In the second Ag site, Ag(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-62°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form AsO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra and  an edgeedge with one As(2)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Ag(1) and one As(1) atom. In the third O site, O(7) is bonded in a bent 120 degrees geometry to one Ag(1) and one As(1) atom. In the fourth O site, O(1) is bonded in a distorted T-shaped geometry to one Ag(2) and two equivalent As(2) atoms. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ag(2) and one As(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Ag(1), two equivalent Ag(2), and one As(2) 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 CIF file [CIF]
data_Ag2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.762
_cell_length_b   6.330
_cell_length_c   8.135
_cell_angle_alpha   60.182
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.874
_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
  Ag  Ag0  1  0.241  0.152  0.435  1.0
  Ag  Ag1  1  0.259  0.152  0.935  1.0
  Ag  Ag2  1  0.759  0.848  0.565  1.0
  Ag  Ag3  1  0.741  0.848  0.065  1.0
  Ag  Ag4  1  0.980  0.058  0.677  1.0
  Ag  Ag5  1  0.520  0.058  0.177  1.0
  Ag  Ag6  1  0.020  0.942  0.323  1.0
  Ag  Ag7  1  0.480  0.942  0.823  1.0
  As  As8  1  0.197  0.639  0.948  1.0
  As  As9  1  0.303  0.639  0.448  1.0
  As  As10  1  0.803  0.361  0.052  1.0
  As  As11  1  0.697  0.361  0.552  1.0
  As  As12  1  0.002  0.500  0.182  1.0
  As  As13  1  0.498  0.500  0.682  1.0
  As  As14  1  0.998  0.500  0.818  1.0
  As  As15  1  0.502  0.500  0.318  1.0
  O  O16  1  0.959  0.695  0.932  1.0
  O  O17  1  0.541  0.695  0.432  1.0
  O  O18  1  0.041  0.305  0.068  1.0
  O  O19  1  0.459  0.305  0.568  1.0
  O  O20  1  0.959  0.678  0.276  1.0
  O  O21  1  0.541  0.678  0.776  1.0
  O  O22  1  0.041  0.322  0.724  1.0
  O  O23  1  0.459  0.322  0.224  1.0
  O  O24  1  0.046  0.220  0.397  1.0
  O  O25  1  0.454  0.220  0.897  1.0
  O  O26  1  0.954  0.780  0.603  1.0
  O  O27  1  0.546  0.780  0.103  1.0
  O  O28  1  0.126  0.655  0.122  1.0
  O  O29  1  0.374  0.655  0.622  1.0
  O  O30  1  0.874  0.345  0.878  1.0
  O  O31  1  0.626  0.345  0.378  1.0
  O  O32  1  0.125  0.656  0.764  1.0
  O  O33  1  0.375  0.656  0.264  1.0
  O  O34  1  0.875  0.344  0.236  1.0
  O  O35  1  0.625  0.344  0.736  1.0
  O  O36  1  0.263  0.376  0.060  1.0
  O  O37  1  0.237  0.376  0.560  1.0
  O  O38  1  0.737  0.624  0.940  1.0
  O  O39  1  0.763  0.624  0.440  1.0
  O  O40  1  0.267  0.899  0.836  1.0
  O  O41  1  0.233  0.899  0.336  1.0
  O  O42  1  0.733  0.101  0.164  1.0
  O  O43  1  0.767  0.101  0.664  1.0
[/CIF]
.
The material described by Ag2As2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 2-coordinate geometry to one O(3), one O(7), and two equivalent O(6) atoms. In the second Ag site, Ag(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-62°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form AsO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra and  an edgeedge with one As(2)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Ag(1) and one As(1) atom. In the third O site, O(7) is bonded in a bent 120 degrees geometry to one Ag(1) and one As(1) atom. In the fourth O site, O(1) is bonded in a distorted T-shaped geometry to one Ag(2) and two equivalent As(2) atoms. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ag(2) and one As(2) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Ag(1), two equivalent Ag(2), and one As(2) 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 CIF file [CIF]
data_Ag2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.762
_cell_length_b   6.330
_cell_length_c   8.135
_cell_angle_alpha   60.182
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   614.874
_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
  Ag  Ag0  1  0.241  0.152  0.435  1.0
  Ag  Ag1  1  0.259  0.152  0.935  1.0
  Ag  Ag2  1  0.759  0.848  0.565  1.0
  Ag  Ag3  1  0.741  0.848  0.065  1.0
  Ag  Ag4  1  0.980  0.058  0.677  1.0
  Ag  Ag5  1  0.520  0.058  0.177  1.0
  Ag  Ag6  1  0.020  0.942  0.323  1.0
  Ag  Ag7  1  0.480  0.942  0.823  1.0
  As  As8  1  0.197  0.639  0.948  1.0
  As  As9  1  0.303  0.639  0.448  1.0
  As  As10  1  0.803  0.361  0.052  1.0
  As  As11  1  0.697  0.361  0.552  1.0
  As  As12  1  0.002  0.500  0.182  1.0
  As  As13  1  0.498  0.500  0.682  1.0
  As  As14  1  0.998  0.500  0.818  1.0
  As  As15  1  0.502  0.500  0.318  1.0
  O  O16  1  0.959  0.695  0.932  1.0
  O  O17  1  0.541  0.695  0.432  1.0
  O  O18  1  0.041  0.305  0.068  1.0
  O  O19  1  0.459  0.305  0.568  1.0
  O  O20  1  0.959  0.678  0.276  1.0
  O  O21  1  0.541  0.678  0.776  1.0
  O  O22  1  0.041  0.322  0.724  1.0
  O  O23  1  0.459  0.322  0.224  1.0
  O  O24  1  0.046  0.220  0.397  1.0
  O  O25  1  0.454  0.220  0.897  1.0
  O  O26  1  0.954  0.780  0.603  1.0
  O  O27  1  0.546  0.780  0.103  1.0
  O  O28  1  0.126  0.655  0.122  1.0
  O  O29  1  0.374  0.655  0.622  1.0
  O  O30  1  0.874  0.345  0.878  1.0
  O  O31  1  0.626  0.345  0.378  1.0
  O  O32  1  0.125  0.656  0.764  1.0
  O  O33  1  0.375  0.656  0.264  1.0
  O  O34  1  0.875  0.344  0.236  1.0
  O  O35  1  0.625  0.344  0.736  1.0
  O  O36  1  0.263  0.376  0.060  1.0
  O  O37  1  0.237  0.376  0.560  1.0
  O  O38  1  0.737  0.624  0.940  1.0
  O  O39  1  0.763  0.624  0.440  1.0
  O  O40  1  0.267  0.899  0.836  1.0
  O  O41  1  0.233  0.899  0.336  1.0
  O  O42  1  0.733  0.101  0.164  1.0
  O  O43  1  0.767  0.101  0.664  1.0
[/CIF]
.