The compound described by Na2Nb4Se4O19 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(6) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(5), one O(8), and two equivalent O(7) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the second Nb site, Nb(2) is bonded to one O(3), one O(4), one O(8), one O(9), and two equivalent O(10) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(1) and one Se(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Nb(1), and one Se(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one Nb(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(1) and one Se(2) atom. In the sixth O site, O(6) is bonded to three equivalent Na(1) and one Se(2) atom to form a mixture of distorted edge and corner-sharing ONa3Se tetrahedra. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Nb(2) atoms. In the tenth O site, O(10) is bonded in a linear geometry to two equivalent Nb(2) atoms. is represented by the CIF card [CIF]
data_Na2Nb4Se4O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.014
_cell_length_b   10.369
_cell_length_c   11.124
_cell_angle_alpha   106.080
_cell_angle_beta   90.053
_cell_angle_gamma   97.421
_symmetry_Int_Tables_number   1
_cell_volume   440.848
_cell_formula_units_Z   1
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
  Na  Na0  1  0.776  0.937  0.861  1.0
  Na  Na1  1  0.224  0.063  0.139  1.0
  Nb  Nb2  1  0.339  0.187  0.704  1.0
  Nb  Nb3  1  0.661  0.813  0.296  1.0
  Nb  Nb4  1  0.568  0.554  0.681  1.0
  Nb  Nb5  1  0.432  0.446  0.319  1.0
  Se  Se6  1  0.344  0.825  0.585  1.0
  Se  Se7  1  0.656  0.175  0.415  1.0
  Se  Se8  1  0.286  0.717  0.987  1.0
  Se  Se9  1  0.714  0.283  0.013  1.0
  O  O10  1  0.646  0.877  0.488  1.0
  O  O11  1  0.354  0.123  0.512  1.0
  O  O12  1  0.318  0.976  0.698  1.0
  O  O13  1  0.682  0.024  0.302  1.0
  O  O14  1  0.603  0.762  0.672  1.0
  O  O15  1  0.397  0.238  0.328  1.0
  O  O16  1  0.564  0.647  0.874  1.0
  O  O17  1  0.436  0.353  0.126  1.0
  O  O18  1  0.604  0.774  0.110  1.0
  O  O19  1  0.396  0.226  0.890  1.0
  O  O20  1  0.245  0.866  0.959  1.0
  O  O21  1  0.755  0.134  0.041  1.0
  O  O22  1  0.880  0.177  0.705  1.0
  O  O23  1  0.120  0.823  0.295  1.0
  O  O24  1  0.457  0.372  0.699  1.0
  O  O25  1  0.543  0.628  0.301  1.0
  O  O26  1  0.500  0.500  0.500  1.0
  O  O27  1  0.029  0.570  0.691  1.0
  O  O28  1  0.971  0.430  0.309  1.0
[/CIF]
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The compound described by Na2Nb4Se4O19 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(6) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(5), one O(8), and two equivalent O(7) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. In the second Nb site, Nb(2) is bonded to one O(3), one O(4), one O(8), one O(9), and two equivalent O(10) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(1) and one Se(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Nb(1), and one Se(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one Nb(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(1) and one Se(2) atom. In the sixth O site, O(6) is bonded to three equivalent Na(1) and one Se(2) atom to form a mixture of distorted edge and corner-sharing ONa3Se tetrahedra. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Nb(1) and one Nb(2) atom. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Nb(2) atoms. In the tenth O site, O(10) is bonded in a linear geometry to two equivalent Nb(2) atoms. is represented by the CIF card [CIF]
data_Na2Nb4Se4O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.014
_cell_length_b   10.369
_cell_length_c   11.124
_cell_angle_alpha   106.080
_cell_angle_beta   90.053
_cell_angle_gamma   97.421
_symmetry_Int_Tables_number   1
_cell_volume   440.848
_cell_formula_units_Z   1
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
  Na  Na0  1  0.776  0.937  0.861  1.0
  Na  Na1  1  0.224  0.063  0.139  1.0
  Nb  Nb2  1  0.339  0.187  0.704  1.0
  Nb  Nb3  1  0.661  0.813  0.296  1.0
  Nb  Nb4  1  0.568  0.554  0.681  1.0
  Nb  Nb5  1  0.432  0.446  0.319  1.0
  Se  Se6  1  0.344  0.825  0.585  1.0
  Se  Se7  1  0.656  0.175  0.415  1.0
  Se  Se8  1  0.286  0.717  0.987  1.0
  Se  Se9  1  0.714  0.283  0.013  1.0
  O  O10  1  0.646  0.877  0.488  1.0
  O  O11  1  0.354  0.123  0.512  1.0
  O  O12  1  0.318  0.976  0.698  1.0
  O  O13  1  0.682  0.024  0.302  1.0
  O  O14  1  0.603  0.762  0.672  1.0
  O  O15  1  0.397  0.238  0.328  1.0
  O  O16  1  0.564  0.647  0.874  1.0
  O  O17  1  0.436  0.353  0.126  1.0
  O  O18  1  0.604  0.774  0.110  1.0
  O  O19  1  0.396  0.226  0.890  1.0
  O  O20  1  0.245  0.866  0.959  1.0
  O  O21  1  0.755  0.134  0.041  1.0
  O  O22  1  0.880  0.177  0.705  1.0
  O  O23  1  0.120  0.823  0.295  1.0
  O  O24  1  0.457  0.372  0.699  1.0
  O  O25  1  0.543  0.628  0.301  1.0
  O  O26  1  0.500  0.500  0.500  1.0
  O  O27  1  0.029  0.570  0.691  1.0
  O  O28  1  0.971  0.430  0.309  1.0
[/CIF]
.