The structure described by Pb2N2SeO9 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(4) atoms. In the second N site, N(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(6) atoms. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to two equivalent Pb(1) and one N(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Pb(1) and one N(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Pb(1) and one N(2) atom. is represented by the CIF file [CIF]
data_Pb2SeN2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.489
_cell_length_b   7.293
_cell_length_c   10.314
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   412.898
_cell_formula_units_Z   2
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
  Pb  Pb0  1  0.500  0.891  0.155  1.0
  Pb  Pb1  1  0.000  0.391  0.845  1.0
  Pb  Pb2  1  0.500  0.072  0.523  1.0
  Pb  Pb3  1  0.000  0.572  0.477  1.0
  Se  Se4  1  0.500  0.636  0.680  1.0
  Se  Se5  1  0.000  0.136  0.320  1.0
  N  N6  1  0.500  0.264  0.999  1.0
  N  N7  1  0.000  0.764  0.001  1.0
  N  N8  1  0.000  0.008  0.719  1.0
  N  N9  1  0.500  0.508  0.281  1.0
  O  O10  1  0.500  0.742  0.532  1.0
  O  O11  1  0.000  0.242  0.468  1.0
  O  O12  1  0.258  0.490  0.658  1.0
  O  O13  1  0.742  0.490  0.658  1.0
  O  O14  1  0.242  0.990  0.342  1.0
  O  O15  1  0.758  0.990  0.342  1.0
  O  O16  1  0.500  0.374  0.905  1.0
  O  O17  1  0.000  0.874  0.095  1.0
  O  O18  1  0.301  0.208  0.046  1.0
  O  O19  1  0.699  0.208  0.046  1.0
  O  O20  1  0.199  0.708  0.954  1.0
  O  O21  1  0.801  0.708  0.954  1.0
  O  O22  1  0.500  0.368  0.350  1.0
  O  O23  1  0.000  0.868  0.650  1.0
  O  O24  1  0.199  0.082  0.753  1.0
  O  O25  1  0.801  0.082  0.753  1.0
  O  O26  1  0.301  0.582  0.247  1.0
  O  O27  1  0.699  0.582  0.247  1.0
[/CIF]
.
The structure described by Pb2N2SeO9 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(4) atoms. In the second N site, N(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(6) atoms. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to two equivalent Pb(1) and one N(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Pb(1) and one N(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Pb(1) and one N(2) atom. is represented by the CIF file [CIF]
data_Pb2SeN2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.489
_cell_length_b   7.293
_cell_length_c   10.314
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   412.898
_cell_formula_units_Z   2
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
  Pb  Pb0  1  0.500  0.891  0.155  1.0
  Pb  Pb1  1  0.000  0.391  0.845  1.0
  Pb  Pb2  1  0.500  0.072  0.523  1.0
  Pb  Pb3  1  0.000  0.572  0.477  1.0
  Se  Se4  1  0.500  0.636  0.680  1.0
  Se  Se5  1  0.000  0.136  0.320  1.0
  N  N6  1  0.500  0.264  0.999  1.0
  N  N7  1  0.000  0.764  0.001  1.0
  N  N8  1  0.000  0.008  0.719  1.0
  N  N9  1  0.500  0.508  0.281  1.0
  O  O10  1  0.500  0.742  0.532  1.0
  O  O11  1  0.000  0.242  0.468  1.0
  O  O12  1  0.258  0.490  0.658  1.0
  O  O13  1  0.742  0.490  0.658  1.0
  O  O14  1  0.242  0.990  0.342  1.0
  O  O15  1  0.758  0.990  0.342  1.0
  O  O16  1  0.500  0.374  0.905  1.0
  O  O17  1  0.000  0.874  0.095  1.0
  O  O18  1  0.301  0.208  0.046  1.0
  O  O19  1  0.699  0.208  0.046  1.0
  O  O20  1  0.199  0.708  0.954  1.0
  O  O21  1  0.801  0.708  0.954  1.0
  O  O22  1  0.500  0.368  0.350  1.0
  O  O23  1  0.000  0.868  0.650  1.0
  O  O24  1  0.199  0.082  0.753  1.0
  O  O25  1  0.801  0.082  0.753  1.0
  O  O26  1  0.301  0.582  0.247  1.0
  O  O27  1  0.699  0.582  0.247  1.0
[/CIF]
.