The crystal structure described by FePbAs2O8 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. Pb(1) is bonded in a 6-coordinate geometry to one O(3), one O(6), one O(7), one O(8), and two equivalent O(4) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Pb(1), and one As(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(1), and one As(2) atom. In the fourth O site, O(8) is bonded in a distorted water-like geometry to one Pb(1) and one As(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the sixth O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(1), and one As(1) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Pb(1) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_FeAs2PbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.470
_cell_length_b   4.947
_cell_length_c   16.097
_cell_angle_alpha   75.395
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   652.668
_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
  Fe  Fe0  1  0.951  0.693  0.646  1.0
  Fe  Fe1  1  0.549  0.693  0.146  1.0
  Fe  Fe2  1  0.049  0.307  0.354  1.0
  Fe  Fe3  1  0.451  0.307  0.854  1.0
  As  As4  1  0.810  0.296  0.519  1.0
  As  As5  1  0.690  0.296  0.019  1.0
  As  As6  1  0.190  0.704  0.481  1.0
  As  As7  1  0.310  0.704  0.981  1.0
  As  As8  1  0.767  0.071  0.767  1.0
  As  As9  1  0.733  0.071  0.267  1.0
  As  As10  1  0.233  0.929  0.233  1.0
  As  As11  1  0.267  0.929  0.733  1.0
  Pb  Pb12  1  0.528  0.752  0.619  1.0
  Pb  Pb13  1  0.972  0.752  0.119  1.0
  Pb  Pb14  1  0.472  0.248  0.381  1.0
  Pb  Pb15  1  0.028  0.248  0.881  1.0
  O  O16  1  0.952  0.076  0.573  1.0
  O  O17  1  0.548  0.076  0.073  1.0
  O  O18  1  0.048  0.924  0.427  1.0
  O  O19  1  0.452  0.924  0.927  1.0
  O  O20  1  0.865  0.420  0.414  1.0
  O  O21  1  0.635  0.420  0.914  1.0
  O  O22  1  0.135  0.580  0.586  1.0
  O  O23  1  0.365  0.580  0.086  1.0
  O  O24  1  0.781  0.559  0.572  1.0
  O  O25  1  0.719  0.559  0.072  1.0
  O  O26  1  0.219  0.441  0.428  1.0
  O  O27  1  0.281  0.441  0.928  1.0
  O  O28  1  0.619  0.157  0.518  1.0
  O  O29  1  0.881  0.157  0.018  1.0
  O  O30  1  0.381  0.843  0.482  1.0
  O  O31  1  0.119  0.843  0.982  1.0
  O  O32  1  0.588  0.238  0.759  1.0
  O  O33  1  0.912  0.238  0.259  1.0
  O  O34  1  0.412  0.762  0.241  1.0
  O  O35  1  0.088  0.762  0.741  1.0
  O  O36  1  0.752  0.845  0.701  1.0
  O  O37  1  0.748  0.845  0.201  1.0
  O  O38  1  0.248  0.155  0.299  1.0
  O  O39  1  0.252  0.155  0.799  1.0
  O  O40  1  0.916  0.323  0.735  1.0
  O  O41  1  0.584  0.323  0.235  1.0
  O  O42  1  0.084  0.677  0.265  1.0
  O  O43  1  0.416  0.677  0.765  1.0
  O  O44  1  0.837  0.913  0.867  1.0
  O  O45  1  0.663  0.913  0.367  1.0
  O  O46  1  0.163  0.087  0.133  1.0
  O  O47  1  0.337  0.087  0.633  1.0
[/CIF]
.
The crystal structure described by FePbAs2O8 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. Pb(1) is bonded in a 6-coordinate geometry to one O(3), one O(6), one O(7), one O(8), and two equivalent O(4) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Fe(1), one Pb(1), and one As(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(1), and one As(2) atom. In the fourth O site, O(8) is bonded in a distorted water-like geometry to one Pb(1) and one As(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the sixth O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one Pb(1), and one As(1) atom. In the eighth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Pb(1) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_FeAs2PbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.470
_cell_length_b   4.947
_cell_length_c   16.097
_cell_angle_alpha   75.395
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   652.668
_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
  Fe  Fe0  1  0.951  0.693  0.646  1.0
  Fe  Fe1  1  0.549  0.693  0.146  1.0
  Fe  Fe2  1  0.049  0.307  0.354  1.0
  Fe  Fe3  1  0.451  0.307  0.854  1.0
  As  As4  1  0.810  0.296  0.519  1.0
  As  As5  1  0.690  0.296  0.019  1.0
  As  As6  1  0.190  0.704  0.481  1.0
  As  As7  1  0.310  0.704  0.981  1.0
  As  As8  1  0.767  0.071  0.767  1.0
  As  As9  1  0.733  0.071  0.267  1.0
  As  As10  1  0.233  0.929  0.233  1.0
  As  As11  1  0.267  0.929  0.733  1.0
  Pb  Pb12  1  0.528  0.752  0.619  1.0
  Pb  Pb13  1  0.972  0.752  0.119  1.0
  Pb  Pb14  1  0.472  0.248  0.381  1.0
  Pb  Pb15  1  0.028  0.248  0.881  1.0
  O  O16  1  0.952  0.076  0.573  1.0
  O  O17  1  0.548  0.076  0.073  1.0
  O  O18  1  0.048  0.924  0.427  1.0
  O  O19  1  0.452  0.924  0.927  1.0
  O  O20  1  0.865  0.420  0.414  1.0
  O  O21  1  0.635  0.420  0.914  1.0
  O  O22  1  0.135  0.580  0.586  1.0
  O  O23  1  0.365  0.580  0.086  1.0
  O  O24  1  0.781  0.559  0.572  1.0
  O  O25  1  0.719  0.559  0.072  1.0
  O  O26  1  0.219  0.441  0.428  1.0
  O  O27  1  0.281  0.441  0.928  1.0
  O  O28  1  0.619  0.157  0.518  1.0
  O  O29  1  0.881  0.157  0.018  1.0
  O  O30  1  0.381  0.843  0.482  1.0
  O  O31  1  0.119  0.843  0.982  1.0
  O  O32  1  0.588  0.238  0.759  1.0
  O  O33  1  0.912  0.238  0.259  1.0
  O  O34  1  0.412  0.762  0.241  1.0
  O  O35  1  0.088  0.762  0.741  1.0
  O  O36  1  0.752  0.845  0.701  1.0
  O  O37  1  0.748  0.845  0.201  1.0
  O  O38  1  0.248  0.155  0.299  1.0
  O  O39  1  0.252  0.155  0.799  1.0
  O  O40  1  0.916  0.323  0.735  1.0
  O  O41  1  0.584  0.323  0.235  1.0
  O  O42  1  0.084  0.677  0.265  1.0
  O  O43  1  0.416  0.677  0.765  1.0
  O  O44  1  0.837  0.913  0.867  1.0
  O  O45  1  0.663  0.913  0.367  1.0
  O  O46  1  0.163  0.087  0.133  1.0
  O  O47  1  0.337  0.087  0.633  1.0
[/CIF]
.