The structure described by SrBi2Nb2O9 crystallizes in the orthorhombic Cmc2_1 space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(1) atoms. Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 20-25°. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(1) atoms. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1) and two equivalent Nb(1) atoms. In the fourth O site, O(3) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(1) atoms. is represented by the CIF card [CIF]
data_SrNb2Bi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.012
_cell_length_b   13.012
_cell_length_c   5.688
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.933
_symmetry_Int_Tables_number   1
_cell_volume   408.080
_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
  Sr  Sr0  1  0.252  0.252  0.017  1.0
  Sr  Sr1  1  0.748  0.748  0.517  1.0
  Nb  Nb2  1  0.834  0.669  0.025  1.0
  Nb  Nb3  1  0.331  0.166  0.525  1.0
  Nb  Nb4  1  0.669  0.834  0.025  1.0
  Nb  Nb5  1  0.166  0.331  0.525  1.0
  Bi  Bi6  1  0.486  0.086  0.934  1.0
  Bi  Bi7  1  0.514  0.914  0.434  1.0
  Bi  Bi8  1  0.914  0.514  0.434  1.0
  Bi  Bi9  1  0.086  0.486  0.934  1.0
  O  O10  1  0.541  0.411  0.284  1.0
  O  O11  1  0.459  0.589  0.784  1.0
  O  O12  1  0.589  0.459  0.784  1.0
  O  O13  1  0.411  0.541  0.284  1.0
  O  O14  1  0.057  0.885  0.331  1.0
  O  O15  1  0.943  0.115  0.831  1.0
  O  O16  1  0.115  0.943  0.831  1.0
  O  O17  1  0.885  0.057  0.331  1.0
  O  O18  1  0.228  0.729  0.226  1.0
  O  O19  1  0.772  0.271  0.726  1.0
  O  O20  1  0.194  0.194  0.566  1.0
  O  O21  1  0.806  0.806  0.066  1.0
  O  O22  1  0.486  0.176  0.562  1.0
  O  O23  1  0.514  0.824  0.062  1.0
  O  O24  1  0.824  0.514  0.062  1.0
  O  O25  1  0.176  0.486  0.562  1.0
  O  O26  1  0.729  0.228  0.226  1.0
  O  O27  1  0.271  0.772  0.726  1.0
[/CIF]
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The structure described by SrBi2Nb2O9 crystallizes in the orthorhombic Cmc2_1 space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(1) atoms. Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 20-25°. Bi(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(1) atoms. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Sr(1) and two equivalent Nb(1) atoms. In the fourth O site, O(3) is bonded to four equivalent Bi(1) atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the fifth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Nb(1) atoms. is represented by the CIF card [CIF]
data_SrNb2Bi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.012
_cell_length_b   13.012
_cell_length_c   5.688
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.933
_symmetry_Int_Tables_number   1
_cell_volume   408.080
_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
  Sr  Sr0  1  0.252  0.252  0.017  1.0
  Sr  Sr1  1  0.748  0.748  0.517  1.0
  Nb  Nb2  1  0.834  0.669  0.025  1.0
  Nb  Nb3  1  0.331  0.166  0.525  1.0
  Nb  Nb4  1  0.669  0.834  0.025  1.0
  Nb  Nb5  1  0.166  0.331  0.525  1.0
  Bi  Bi6  1  0.486  0.086  0.934  1.0
  Bi  Bi7  1  0.514  0.914  0.434  1.0
  Bi  Bi8  1  0.914  0.514  0.434  1.0
  Bi  Bi9  1  0.086  0.486  0.934  1.0
  O  O10  1  0.541  0.411  0.284  1.0
  O  O11  1  0.459  0.589  0.784  1.0
  O  O12  1  0.589  0.459  0.784  1.0
  O  O13  1  0.411  0.541  0.284  1.0
  O  O14  1  0.057  0.885  0.331  1.0
  O  O15  1  0.943  0.115  0.831  1.0
  O  O16  1  0.115  0.943  0.831  1.0
  O  O17  1  0.885  0.057  0.331  1.0
  O  O18  1  0.228  0.729  0.226  1.0
  O  O19  1  0.772  0.271  0.726  1.0
  O  O20  1  0.194  0.194  0.566  1.0
  O  O21  1  0.806  0.806  0.066  1.0
  O  O22  1  0.486  0.176  0.562  1.0
  O  O23  1  0.514  0.824  0.062  1.0
  O  O24  1  0.824  0.514  0.062  1.0
  O  O25  1  0.176  0.486  0.562  1.0
  O  O26  1  0.729  0.228  0.226  1.0
  O  O27  1  0.271  0.772  0.726  1.0
[/CIF]
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