The material described by BiAs2O7 crystallizes in the monoclinic P2_1/c space group. Bi(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form BiO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. 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  a cornercorner with one As(2)O4 tetrahedra and corners with two equivalent Bi(1)O5 trigonal bipyramids. 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  a cornercorner with one As(1)O4 tetrahedra and corners with three equivalent Bi(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Bi(1) and one As(1) atom. In the second O site, O(7) is bonded in a bent 120 degrees geometry to one Bi(1) and one As(2) atom. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Bi(1) and one As(2) atom. In the fourth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(1) atom. In the fifth O site, O(3) is bonded in a single-bond geometry to one As(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one As(1) and one As(2) atom. In the seventh O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(2) atom. is represented by the CIF file [CIF]
data_BiAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.916
_cell_length_b   7.598
_cell_length_c   10.187
_cell_angle_alpha   70.567
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   723.741
_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
  Bi  Bi0  1  0.934  0.187  0.710  1.0
  Bi  Bi1  1  0.434  0.813  0.790  1.0
  Bi  Bi2  1  0.066  0.813  0.290  1.0
  Bi  Bi3  1  0.566  0.187  0.210  1.0
  As  As4  1  0.749  0.590  0.745  1.0
  As  As5  1  0.249  0.410  0.755  1.0
  As  As6  1  0.251  0.410  0.255  1.0
  As  As7  1  0.751  0.590  0.245  1.0
  As  As8  1  0.710  0.967  0.967  1.0
  As  As9  1  0.210  0.033  0.533  1.0
  As  As10  1  0.290  0.033  0.033  1.0
  As  As11  1  0.790  0.967  0.467  1.0
  O  O12  1  0.692  0.137  0.041  1.0
  O  O13  1  0.192  0.863  0.459  1.0
  O  O14  1  0.308  0.863  0.959  1.0
  O  O15  1  0.808  0.137  0.541  1.0
  O  O16  1  0.576  0.627  0.728  1.0
  O  O17  1  0.076  0.373  0.772  1.0
  O  O18  1  0.424  0.373  0.272  1.0
  O  O19  1  0.924  0.627  0.228  1.0
  O  O20  1  0.820  0.622  0.884  1.0
  O  O21  1  0.320  0.378  0.616  1.0
  O  O22  1  0.180  0.378  0.116  1.0
  O  O23  1  0.680  0.622  0.384  1.0
  O  O24  1  0.831  0.749  0.589  1.0
  O  O25  1  0.331  0.251  0.911  1.0
  O  O26  1  0.169  0.251  0.411  1.0
  O  O27  1  0.669  0.749  0.089  1.0
  O  O28  1  0.898  0.994  0.331  1.0
  O  O29  1  0.398  0.006  0.169  1.0
  O  O30  1  0.102  0.006  0.669  1.0
  O  O31  1  0.602  0.994  0.831  1.0
  O  O32  1  0.732  0.379  0.218  1.0
  O  O33  1  0.232  0.621  0.282  1.0
  O  O34  1  0.268  0.621  0.782  1.0
  O  O35  1  0.768  0.379  0.718  1.0
  O  O36  1  0.624  0.980  0.409  1.0
  O  O37  1  0.124  0.020  0.091  1.0
  O  O38  1  0.376  0.020  0.591  1.0
  O  O39  1  0.876  0.980  0.909  1.0
[/CIF]
.
The material described by BiAs2O7 crystallizes in the monoclinic P2_1/c space group. Bi(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form BiO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. 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  a cornercorner with one As(2)O4 tetrahedra and corners with two equivalent Bi(1)O5 trigonal bipyramids. 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  a cornercorner with one As(1)O4 tetrahedra and corners with three equivalent Bi(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Bi(1) and one As(1) atom. In the second O site, O(7) is bonded in a bent 120 degrees geometry to one Bi(1) and one As(2) atom. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Bi(1) and one As(2) atom. In the fourth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(1) atom. In the fifth O site, O(3) is bonded in a single-bond geometry to one As(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one As(1) and one As(2) atom. In the seventh O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Bi(1) and one As(2) atom. is represented by the CIF file [CIF]
data_BiAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.916
_cell_length_b   7.598
_cell_length_c   10.187
_cell_angle_alpha   70.567
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   723.741
_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
  Bi  Bi0  1  0.934  0.187  0.710  1.0
  Bi  Bi1  1  0.434  0.813  0.790  1.0
  Bi  Bi2  1  0.066  0.813  0.290  1.0
  Bi  Bi3  1  0.566  0.187  0.210  1.0
  As  As4  1  0.749  0.590  0.745  1.0
  As  As5  1  0.249  0.410  0.755  1.0
  As  As6  1  0.251  0.410  0.255  1.0
  As  As7  1  0.751  0.590  0.245  1.0
  As  As8  1  0.710  0.967  0.967  1.0
  As  As9  1  0.210  0.033  0.533  1.0
  As  As10  1  0.290  0.033  0.033  1.0
  As  As11  1  0.790  0.967  0.467  1.0
  O  O12  1  0.692  0.137  0.041  1.0
  O  O13  1  0.192  0.863  0.459  1.0
  O  O14  1  0.308  0.863  0.959  1.0
  O  O15  1  0.808  0.137  0.541  1.0
  O  O16  1  0.576  0.627  0.728  1.0
  O  O17  1  0.076  0.373  0.772  1.0
  O  O18  1  0.424  0.373  0.272  1.0
  O  O19  1  0.924  0.627  0.228  1.0
  O  O20  1  0.820  0.622  0.884  1.0
  O  O21  1  0.320  0.378  0.616  1.0
  O  O22  1  0.180  0.378  0.116  1.0
  O  O23  1  0.680  0.622  0.384  1.0
  O  O24  1  0.831  0.749  0.589  1.0
  O  O25  1  0.331  0.251  0.911  1.0
  O  O26  1  0.169  0.251  0.411  1.0
  O  O27  1  0.669  0.749  0.089  1.0
  O  O28  1  0.898  0.994  0.331  1.0
  O  O29  1  0.398  0.006  0.169  1.0
  O  O30  1  0.102  0.006  0.669  1.0
  O  O31  1  0.602  0.994  0.831  1.0
  O  O32  1  0.732  0.379  0.218  1.0
  O  O33  1  0.232  0.621  0.282  1.0
  O  O34  1  0.268  0.621  0.782  1.0
  O  O35  1  0.768  0.379  0.718  1.0
  O  O36  1  0.624  0.980  0.409  1.0
  O  O37  1  0.124  0.020  0.091  1.0
  O  O38  1  0.376  0.020  0.591  1.0
  O  O39  1  0.876  0.980  0.909  1.0
[/CIF]
.