The material described by Cu2AsO8 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(6) and two equivalent O(7) atoms. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted CuO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(3), one O(4), one O(5), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-58°. There are eight inequivalent O sites. In the first O site, O(6) is bonded in an L-shaped geometry to two equivalent Cu(1) atoms. In the second O site, O(7) is bonded in a trigonal non-coplanar geometry to one Cu(2) and two equivalent Cu(1) atoms. In the third O site, O(8) is bonded in a water-like geometry to one As(1) and one O(1) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one O(8) atom. In the fifth O site, O(2) is bonded in a single-bond geometry to one Cu(2) atom. In the sixth O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one As(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Cu(2) and one As(1) atom. In the eighth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cu(2) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2AsO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.484
_cell_length_b   10.429
_cell_length_c   12.208
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   698.184
_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
  Cu  Cu0  1  0.534  0.749  0.506  1.0
  Cu  Cu1  1  0.034  0.751  0.494  1.0
  Cu  Cu2  1  0.466  0.249  0.994  1.0
  Cu  Cu3  1  0.966  0.251  0.006  1.0
  Cu  Cu4  1  0.855  0.788  0.725  1.0
  Cu  Cu5  1  0.355  0.712  0.275  1.0
  Cu  Cu6  1  0.145  0.288  0.775  1.0
  Cu  Cu7  1  0.645  0.212  0.225  1.0
  As  As8  1  0.295  0.586  0.740  1.0
  As  As9  1  0.795  0.914  0.260  1.0
  As  As10  1  0.705  0.086  0.760  1.0
  As  As11  1  0.205  0.414  0.240  1.0
  O  O12  1  0.986  0.218  0.596  1.0
  O  O13  1  0.486  0.282  0.404  1.0
  O  O14  1  0.014  0.718  0.904  1.0
  O  O15  1  0.514  0.782  0.096  1.0
  O  O16  1  0.144  0.880  0.725  1.0
  O  O17  1  0.644  0.620  0.275  1.0
  O  O18  1  0.856  0.380  0.775  1.0
  O  O19  1  0.356  0.120  0.225  1.0
  O  O20  1  0.649  0.928  0.779  1.0
  O  O21  1  0.149  0.572  0.221  1.0
  O  O22  1  0.351  0.428  0.721  1.0
  O  O23  1  0.851  0.072  0.279  1.0
  O  O24  1  0.536  0.682  0.722  1.0
  O  O25  1  0.036  0.818  0.278  1.0
  O  O26  1  0.464  0.182  0.778  1.0
  O  O27  1  0.964  0.318  0.222  1.0
  O  O28  1  0.023  0.630  0.683  1.0
  O  O29  1  0.523  0.870  0.317  1.0
  O  O30  1  0.977  0.130  0.817  1.0
  O  O31  1  0.477  0.370  0.183  1.0
  O  O32  1  0.277  0.850  0.552  1.0
  O  O33  1  0.777  0.650  0.448  1.0
  O  O34  1  0.723  0.350  0.948  1.0
  O  O35  1  0.223  0.150  0.052  1.0
  O  O36  1  0.791  0.837  0.567  1.0
  O  O37  1  0.291  0.663  0.433  1.0
  O  O38  1  0.209  0.337  0.933  1.0
  O  O39  1  0.709  0.163  0.067  1.0
  O  O40  1  0.184  0.633  0.903  1.0
  O  O41  1  0.684  0.867  0.097  1.0
  O  O42  1  0.816  0.133  0.597  1.0
  O  O43  1  0.316  0.367  0.403  1.0
[/CIF]
.
The material described by Cu2AsO8 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(6) and two equivalent O(7) atoms. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form distorted CuO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(3), one O(4), one O(5), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-58°. There are eight inequivalent O sites. In the first O site, O(6) is bonded in an L-shaped geometry to two equivalent Cu(1) atoms. In the second O site, O(7) is bonded in a trigonal non-coplanar geometry to one Cu(2) and two equivalent Cu(1) atoms. In the third O site, O(8) is bonded in a water-like geometry to one As(1) and one O(1) atom. In the fourth O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one O(8) atom. In the fifth O site, O(2) is bonded in a single-bond geometry to one Cu(2) atom. In the sixth O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one As(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Cu(2) and one As(1) atom. In the eighth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cu(2) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cu2AsO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.484
_cell_length_b   10.429
_cell_length_c   12.208
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   698.184
_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
  Cu  Cu0  1  0.534  0.749  0.506  1.0
  Cu  Cu1  1  0.034  0.751  0.494  1.0
  Cu  Cu2  1  0.466  0.249  0.994  1.0
  Cu  Cu3  1  0.966  0.251  0.006  1.0
  Cu  Cu4  1  0.855  0.788  0.725  1.0
  Cu  Cu5  1  0.355  0.712  0.275  1.0
  Cu  Cu6  1  0.145  0.288  0.775  1.0
  Cu  Cu7  1  0.645  0.212  0.225  1.0
  As  As8  1  0.295  0.586  0.740  1.0
  As  As9  1  0.795  0.914  0.260  1.0
  As  As10  1  0.705  0.086  0.760  1.0
  As  As11  1  0.205  0.414  0.240  1.0
  O  O12  1  0.986  0.218  0.596  1.0
  O  O13  1  0.486  0.282  0.404  1.0
  O  O14  1  0.014  0.718  0.904  1.0
  O  O15  1  0.514  0.782  0.096  1.0
  O  O16  1  0.144  0.880  0.725  1.0
  O  O17  1  0.644  0.620  0.275  1.0
  O  O18  1  0.856  0.380  0.775  1.0
  O  O19  1  0.356  0.120  0.225  1.0
  O  O20  1  0.649  0.928  0.779  1.0
  O  O21  1  0.149  0.572  0.221  1.0
  O  O22  1  0.351  0.428  0.721  1.0
  O  O23  1  0.851  0.072  0.279  1.0
  O  O24  1  0.536  0.682  0.722  1.0
  O  O25  1  0.036  0.818  0.278  1.0
  O  O26  1  0.464  0.182  0.778  1.0
  O  O27  1  0.964  0.318  0.222  1.0
  O  O28  1  0.023  0.630  0.683  1.0
  O  O29  1  0.523  0.870  0.317  1.0
  O  O30  1  0.977  0.130  0.817  1.0
  O  O31  1  0.477  0.370  0.183  1.0
  O  O32  1  0.277  0.850  0.552  1.0
  O  O33  1  0.777  0.650  0.448  1.0
  O  O34  1  0.723  0.350  0.948  1.0
  O  O35  1  0.223  0.150  0.052  1.0
  O  O36  1  0.791  0.837  0.567  1.0
  O  O37  1  0.291  0.663  0.433  1.0
  O  O38  1  0.209  0.337  0.933  1.0
  O  O39  1  0.709  0.163  0.067  1.0
  O  O40  1  0.184  0.633  0.903  1.0
  O  O41  1  0.684  0.867  0.097  1.0
  O  O42  1  0.816  0.133  0.597  1.0
  O  O43  1  0.316  0.367  0.403  1.0
[/CIF]
.