The material structure described by Bi5AgNb4O18 crystallizes in the monoclinic Cm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(9) atom to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(6) atom to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 27-34°. Ag(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(10), one O(9), two equivalent O(7), and two equivalent O(8) atoms. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(10), one O(9), two equivalent O(7), and two equivalent O(8) atoms. There are ten inequivalent O sites. In the first O site, O(8) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(9) is bonded in a distorted single-bond geometry to one Nb(1), one Bi(2), and one Bi(3) atom. In the third O site, O(10) is bonded in a distorted single-bond geometry to one Nb(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), one Ag(1), and one Bi(1) atom. In the fifth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Nb(1), one Nb(2), one Ag(1), and one Bi(1) atom. In the sixth O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Nb(1), one Ag(1), and one Bi(1) atom. In the seventh O site, O(4) is bonded in a distorted tetrahedral geometry to two equivalent Nb(2), one Ag(1), and one Bi(1) atom. In the eighth O site, O(5) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Bi(1) atom. In the ninth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Nb(1), one Nb(2), and one Ag(1) atom. In the tenth O site, O(7) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. is represented by the CIF card [CIF]
data_Nb4AgBi5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.937
_cell_length_b   12.937
_cell_length_c   5.608
_cell_angle_alpha   89.830
_cell_angle_beta   89.830
_cell_angle_gamma   155.136
_symmetry_Int_Tables_number   1
_cell_volume   394.627
_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
  Nb  Nb0  1  0.655  0.826  0.535  1.0
  Nb  Nb1  1  0.826  0.655  0.535  1.0
  Nb  Nb2  1  0.329  0.160  0.041  1.0
  Nb  Nb3  1  0.160  0.329  0.041  1.0
  Ag  Ag4  1  0.241  0.241  0.529  1.0
  Bi  Bi5  1  0.725  0.725  0.990  1.0
  Bi  Bi6  1  0.019  0.419  0.490  1.0
  Bi  Bi7  1  0.419  0.019  0.490  1.0
  Bi  Bi8  1  0.982  0.582  0.990  1.0
  Bi  Bi9  1  0.582  0.982  0.990  1.0
  O  O10  1  0.975  0.110  0.780  1.0
  O  O11  1  0.110  0.975  0.780  1.0
  O  O12  1  0.025  0.888  0.272  1.0
  O  O13  1  0.888  0.025  0.272  1.0
  O  O14  1  0.690  0.690  0.594  1.0
  O  O15  1  0.329  0.329  0.083  1.0
  O  O16  1  0.473  0.645  0.870  1.0
  O  O17  1  0.645  0.473  0.870  1.0
  O  O18  1  0.546  0.363  0.361  1.0
  O  O19  1  0.363  0.546  0.361  1.0
  O  O20  1  0.263  0.759  0.766  1.0
  O  O21  1  0.759  0.263  0.766  1.0
  O  O22  1  0.739  0.242  0.265  1.0
  O  O23  1  0.242  0.739  0.265  1.0
  O  O24  1  0.666  0.982  0.575  1.0
  O  O25  1  0.982  0.666  0.575  1.0
  O  O26  1  0.340  0.024  0.065  1.0
  O  O27  1  0.024  0.340  0.065  1.0
[/CIF]
.
The material structure described by Bi5AgNb4O18 crystallizes in the monoclinic Cm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(9) atom to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. In the second Nb site, Nb(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(6) atom to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 27-34°. Ag(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(10), one O(9), two equivalent O(7), and two equivalent O(8) atoms. In the third Bi site, Bi(3) is bonded in a 6-coordinate geometry to one O(10), one O(9), two equivalent O(7), and two equivalent O(8) atoms. There are ten inequivalent O sites. In the first O site, O(8) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(9) is bonded in a distorted single-bond geometry to one Nb(1), one Bi(2), and one Bi(3) atom. In the third O site, O(10) is bonded in a distorted single-bond geometry to one Nb(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(2), one Ag(1), and one Bi(1) atom. In the fifth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Nb(1), one Nb(2), one Ag(1), and one Bi(1) atom. In the sixth O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Nb(1), one Ag(1), and one Bi(1) atom. In the seventh O site, O(4) is bonded in a distorted tetrahedral geometry to two equivalent Nb(2), one Ag(1), and one Bi(1) atom. In the eighth O site, O(5) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Bi(1) atom. In the ninth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Nb(1), one Nb(2), and one Ag(1) atom. In the tenth O site, O(7) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. is represented by the CIF card [CIF]
data_Nb4AgBi5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.937
_cell_length_b   12.937
_cell_length_c   5.608
_cell_angle_alpha   89.830
_cell_angle_beta   89.830
_cell_angle_gamma   155.136
_symmetry_Int_Tables_number   1
_cell_volume   394.627
_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
  Nb  Nb0  1  0.655  0.826  0.535  1.0
  Nb  Nb1  1  0.826  0.655  0.535  1.0
  Nb  Nb2  1  0.329  0.160  0.041  1.0
  Nb  Nb3  1  0.160  0.329  0.041  1.0
  Ag  Ag4  1  0.241  0.241  0.529  1.0
  Bi  Bi5  1  0.725  0.725  0.990  1.0
  Bi  Bi6  1  0.019  0.419  0.490  1.0
  Bi  Bi7  1  0.419  0.019  0.490  1.0
  Bi  Bi8  1  0.982  0.582  0.990  1.0
  Bi  Bi9  1  0.582  0.982  0.990  1.0
  O  O10  1  0.975  0.110  0.780  1.0
  O  O11  1  0.110  0.975  0.780  1.0
  O  O12  1  0.025  0.888  0.272  1.0
  O  O13  1  0.888  0.025  0.272  1.0
  O  O14  1  0.690  0.690  0.594  1.0
  O  O15  1  0.329  0.329  0.083  1.0
  O  O16  1  0.473  0.645  0.870  1.0
  O  O17  1  0.645  0.473  0.870  1.0
  O  O18  1  0.546  0.363  0.361  1.0
  O  O19  1  0.363  0.546  0.361  1.0
  O  O20  1  0.263  0.759  0.766  1.0
  O  O21  1  0.759  0.263  0.766  1.0
  O  O22  1  0.739  0.242  0.265  1.0
  O  O23  1  0.242  0.739  0.265  1.0
  O  O24  1  0.666  0.982  0.575  1.0
  O  O25  1  0.982  0.666  0.575  1.0
  O  O26  1  0.340  0.024  0.065  1.0
  O  O27  1  0.024  0.340  0.065  1.0
[/CIF]
.