The material structure described by Ag2Nb4O11 crystallizes in the trigonal R-3c space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form distorted NbO7 pentagonal bipyramids that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(1)O7 pentagonal bipyramids, and edges with four equivalent Nb(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. In the second Nb site, Nb(2) is bonded to six equivalent O(1) atoms to form corner-sharing NbO6 octahedra. Ag(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), and two equivalent Ag(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent Nb(1) atoms. is represented by the CIF file [CIF]
data_Nb4Ag2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.044
_cell_length_b   13.044
_cell_length_c   13.044
_cell_angle_alpha   27.953
_cell_angle_beta   27.953
_cell_angle_gamma   27.953
_symmetry_Int_Tables_number   1
_cell_volume   430.701
_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
  Nb  Nb0  1  0.386  0.114  0.750  1.0
  Nb  Nb1  1  0.750  0.386  0.114  1.0
  Nb  Nb2  1  0.114  0.750  0.386  1.0
  Nb  Nb3  1  0.250  0.614  0.886  1.0
  Nb  Nb4  1  0.886  0.250  0.614  1.0
  Nb  Nb5  1  0.614  0.886  0.250  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Nb  Nb7  1  0.500  0.500  0.500  1.0
  Ag  Ag8  1  0.671  0.671  0.671  1.0
  Ag  Ag9  1  0.171  0.171  0.171  1.0
  Ag  Ag10  1  0.329  0.329  0.329  1.0
  Ag  Ag11  1  0.829  0.829  0.829  1.0
  O  O12  1  0.745  0.436  0.226  1.0
  O  O13  1  0.226  0.745  0.436  1.0
  O  O14  1  0.436  0.226  0.745  1.0
  O  O15  1  0.726  0.936  0.245  1.0
  O  O16  1  0.245  0.726  0.936  1.0
  O  O17  1  0.936  0.245  0.726  1.0
  O  O18  1  0.255  0.564  0.774  1.0
  O  O19  1  0.774  0.255  0.564  1.0
  O  O20  1  0.564  0.774  0.255  1.0
  O  O21  1  0.274  0.064  0.755  1.0
  O  O22  1  0.755  0.274  0.064  1.0
  O  O23  1  0.064  0.755  0.274  1.0
  O  O24  1  0.999  0.501  0.750  1.0
  O  O25  1  0.750  0.999  0.501  1.0
  O  O26  1  0.501  0.750  0.999  1.0
  O  O27  1  0.250  0.001  0.499  1.0
  O  O28  1  0.499  0.250  0.001  1.0
  O  O29  1  0.001  0.499  0.250  1.0
  O  O30  1  0.593  0.593  0.593  1.0
  O  O31  1  0.093  0.093  0.093  1.0
  O  O32  1  0.407  0.407  0.407  1.0
  O  O33  1  0.907  0.907  0.907  1.0
[/CIF]
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The material structure described by Ag2Nb4O11 crystallizes in the trigonal R-3c space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form distorted NbO7 pentagonal bipyramids that share corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(1)O7 pentagonal bipyramids, and edges with four equivalent Nb(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. In the second Nb site, Nb(2) is bonded to six equivalent O(1) atoms to form corner-sharing NbO6 octahedra. Ag(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), and two equivalent Ag(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent Nb(1) atoms. is represented by the CIF file [CIF]
data_Nb4Ag2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.044
_cell_length_b   13.044
_cell_length_c   13.044
_cell_angle_alpha   27.953
_cell_angle_beta   27.953
_cell_angle_gamma   27.953
_symmetry_Int_Tables_number   1
_cell_volume   430.701
_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
  Nb  Nb0  1  0.386  0.114  0.750  1.0
  Nb  Nb1  1  0.750  0.386  0.114  1.0
  Nb  Nb2  1  0.114  0.750  0.386  1.0
  Nb  Nb3  1  0.250  0.614  0.886  1.0
  Nb  Nb4  1  0.886  0.250  0.614  1.0
  Nb  Nb5  1  0.614  0.886  0.250  1.0
  Nb  Nb6  1  0.000  0.000  0.000  1.0
  Nb  Nb7  1  0.500  0.500  0.500  1.0
  Ag  Ag8  1  0.671  0.671  0.671  1.0
  Ag  Ag9  1  0.171  0.171  0.171  1.0
  Ag  Ag10  1  0.329  0.329  0.329  1.0
  Ag  Ag11  1  0.829  0.829  0.829  1.0
  O  O12  1  0.745  0.436  0.226  1.0
  O  O13  1  0.226  0.745  0.436  1.0
  O  O14  1  0.436  0.226  0.745  1.0
  O  O15  1  0.726  0.936  0.245  1.0
  O  O16  1  0.245  0.726  0.936  1.0
  O  O17  1  0.936  0.245  0.726  1.0
  O  O18  1  0.255  0.564  0.774  1.0
  O  O19  1  0.774  0.255  0.564  1.0
  O  O20  1  0.564  0.774  0.255  1.0
  O  O21  1  0.274  0.064  0.755  1.0
  O  O22  1  0.755  0.274  0.064  1.0
  O  O23  1  0.064  0.755  0.274  1.0
  O  O24  1  0.999  0.501  0.750  1.0
  O  O25  1  0.750  0.999  0.501  1.0
  O  O26  1  0.501  0.750  0.999  1.0
  O  O27  1  0.250  0.001  0.499  1.0
  O  O28  1  0.499  0.250  0.001  1.0
  O  O29  1  0.001  0.499  0.250  1.0
  O  O30  1  0.593  0.593  0.593  1.0
  O  O31  1  0.093  0.093  0.093  1.0
  O  O32  1  0.407  0.407  0.407  1.0
  O  O33  1  0.907  0.907  0.907  1.0
[/CIF]
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