The material described by NaTa4Bi5O18 crystallizes in the monoclinic Cm space group. Na(1) is bonded in a 8-coordinate geometry to one O(7), one O(8), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 24-29°. In the second Ta site, Ta(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(8) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 23-29°. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one O(7), one O(8), two equivalent O(1), two equivalent O(5), and two equivalent O(6) 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(3), and two equivalent O(4) 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(3), and two equivalent O(4) atoms. There are ten inequivalent O sites. In the first O site, O(7) is bonded in a distorted tetrahedral geometry to one Na(1), two equivalent Ta(1), and one Bi(1) atom. In the second O site, O(8) is bonded in a distorted see-saw-like geometry to one Na(1), two equivalent Ta(2), and one Bi(1) atom. In the third O site, O(9) is bonded in a distorted single-bond geometry to one Ta(1), one Bi(2), and one Bi(3) atom. In the fourth O site, O(10) is bonded in a distorted single-bond geometry to one Ta(2), one Bi(2), and one Bi(3) atom. In the fifth O site, O(1) is bonded in a distorted T-shaped geometry to one Ta(1), one Ta(2), and one Bi(1) atom. In the sixth O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Ta(1), and one Ta(2) atom. In the seventh O site, O(3) 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 eighth O site, O(4) 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 ninth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ta(1), one Ta(2), and one Bi(1) atom. In the tenth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Ta(1), one Ta(2), and one Bi(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaTa4Bi5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.958
_cell_length_b   12.958
_cell_length_c   5.550
_cell_angle_alpha   89.992
_cell_angle_beta   89.992
_cell_angle_gamma   155.480
_symmetry_Int_Tables_number   1
_cell_volume   386.767
_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  0.252  0.252  0.489  1.0
  Ta  Ta1  1  0.336  0.169  0.956  1.0
  Ta  Ta2  1  0.169  0.336  0.956  1.0
  Ta  Ta3  1  0.668  0.836  0.463  1.0
  Ta  Ta4  1  0.836  0.668  0.463  1.0
  Bi  Bi5  1  0.764  0.764  0.012  1.0
  Bi  Bi6  1  0.521  0.920  0.011  1.0
  Bi  Bi7  1  0.920  0.521  0.011  1.0
  Bi  Bi8  1  0.478  0.079  0.511  1.0
  Bi  Bi9  1  0.079  0.478  0.511  1.0
  O  O10  1  0.862  0.033  0.145  1.0
  O  O11  1  0.033  0.862  0.145  1.0
  O  O12  1  0.133  0.957  0.651  1.0
  O  O13  1  0.957  0.133  0.651  1.0
  O  O14  1  0.742  0.239  0.241  1.0
  O  O15  1  0.239  0.742  0.241  1.0
  O  O16  1  0.258  0.760  0.741  1.0
  O  O17  1  0.760  0.258  0.741  1.0
  O  O18  1  0.401  0.532  0.224  1.0
  O  O19  1  0.532  0.401  0.224  1.0
  O  O20  1  0.605  0.472  0.732  1.0
  O  O21  1  0.472  0.605  0.732  1.0
  O  O22  1  0.173  0.173  0.933  1.0
  O  O23  1  0.815  0.815  0.416  1.0
  O  O24  1  0.475  0.161  0.947  1.0
  O  O25  1  0.161  0.475  0.947  1.0
  O  O26  1  0.523  0.837  0.444  1.0
  O  O27  1  0.837  0.523  0.444  1.0
[/CIF]
.
The material described by NaTa4Bi5O18 crystallizes in the monoclinic Cm space group. Na(1) is bonded in a 8-coordinate geometry to one O(7), one O(8), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 24-29°. In the second Ta site, Ta(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(8) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 23-29°. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to one O(7), one O(8), two equivalent O(1), two equivalent O(5), and two equivalent O(6) 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(3), and two equivalent O(4) 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(3), and two equivalent O(4) atoms. There are ten inequivalent O sites. In the first O site, O(7) is bonded in a distorted tetrahedral geometry to one Na(1), two equivalent Ta(1), and one Bi(1) atom. In the second O site, O(8) is bonded in a distorted see-saw-like geometry to one Na(1), two equivalent Ta(2), and one Bi(1) atom. In the third O site, O(9) is bonded in a distorted single-bond geometry to one Ta(1), one Bi(2), and one Bi(3) atom. In the fourth O site, O(10) is bonded in a distorted single-bond geometry to one Ta(2), one Bi(2), and one Bi(3) atom. In the fifth O site, O(1) is bonded in a distorted T-shaped geometry to one Ta(1), one Ta(2), and one Bi(1) atom. In the sixth O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Ta(1), and one Ta(2) atom. In the seventh O site, O(3) 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 eighth O site, O(4) 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 ninth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ta(1), one Ta(2), and one Bi(1) atom. In the tenth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Ta(1), one Ta(2), and one Bi(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaTa4Bi5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.958
_cell_length_b   12.958
_cell_length_c   5.550
_cell_angle_alpha   89.992
_cell_angle_beta   89.992
_cell_angle_gamma   155.480
_symmetry_Int_Tables_number   1
_cell_volume   386.767
_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  0.252  0.252  0.489  1.0
  Ta  Ta1  1  0.336  0.169  0.956  1.0
  Ta  Ta2  1  0.169  0.336  0.956  1.0
  Ta  Ta3  1  0.668  0.836  0.463  1.0
  Ta  Ta4  1  0.836  0.668  0.463  1.0
  Bi  Bi5  1  0.764  0.764  0.012  1.0
  Bi  Bi6  1  0.521  0.920  0.011  1.0
  Bi  Bi7  1  0.920  0.521  0.011  1.0
  Bi  Bi8  1  0.478  0.079  0.511  1.0
  Bi  Bi9  1  0.079  0.478  0.511  1.0
  O  O10  1  0.862  0.033  0.145  1.0
  O  O11  1  0.033  0.862  0.145  1.0
  O  O12  1  0.133  0.957  0.651  1.0
  O  O13  1  0.957  0.133  0.651  1.0
  O  O14  1  0.742  0.239  0.241  1.0
  O  O15  1  0.239  0.742  0.241  1.0
  O  O16  1  0.258  0.760  0.741  1.0
  O  O17  1  0.760  0.258  0.741  1.0
  O  O18  1  0.401  0.532  0.224  1.0
  O  O19  1  0.532  0.401  0.224  1.0
  O  O20  1  0.605  0.472  0.732  1.0
  O  O21  1  0.472  0.605  0.732  1.0
  O  O22  1  0.173  0.173  0.933  1.0
  O  O23  1  0.815  0.815  0.416  1.0
  O  O24  1  0.475  0.161  0.947  1.0
  O  O25  1  0.161  0.475  0.947  1.0
  O  O26  1  0.523  0.837  0.444  1.0
  O  O27  1  0.837  0.523  0.444  1.0
[/CIF]
.