data_1000287
_chemical_name_systematic
;
Tetracaesium bis(oxoniobium) catena-octasilicate
;
_chemical_formula_structural       'Cs4 (Nb O)2 (Si8 O21)'
_chemical_formula_sum              'Cs4 Nb2 O23 Si8'
_publ_section_title
;
Synthesis and structure of a novel polysilicate
Cs~4~(NbO)~2~(Si~8~O~21~)
;
loop_
_publ_author_name
  'Crosnier, M P'
  'Guyomard, D'
  'Verbaere, A'
  'Piffard, Y'
_journal_name_full
;
European Journal of Solid State Inorganic Chemistry
;
_journal_coden_ASTM                EJSCE5
_journal_volume                    27
_journal_year                      1990
_journal_page_first                435
_journal_page_last                 442
_cell_length_a                     7.016(2)
_cell_length_b                     7.840(2)
_cell_length_c                     11.066(2)
_cell_angle_alpha                  77.16(2)
_cell_angle_beta                   89.95(2)
_cell_angle_gamma                  72.02(2)
_cell_volume                       563.0
_cell_formula_units_Z              1
_symmetry_space_group_name_H-M     'P -1'
_symmetry_Int_Tables_number        2
_symmetry_cell_setting             triclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Cs1+   1.000
  Nb5+   5.000
  Si4+   4.000
  O2-   -2.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Cs1   Cs1+   2 i 0.2095(1) 0.2096(1) 0.01373(7) 1.  0 d
  Cs2   Cs1+   2 i 0.1750(1) 0.2818(1) 0.36388(7) 1.  0 d
  Nb1   Nb5+   2 i 0.7053(1) 0.2591(1) 0.18545(9) 1.  0 d
  Si1   Si4+   2 i 0.6488(4) 0.2962(4) 0.5012(3) 1.  0 d
  Si2   Si4+   2 i 0.4339(4) 0.1404(4) 0.7125(3) 1.  0 d
  Si3   Si4+   2 i 0.6605(4) 0.3301(4) 0.8693(3) 1.  0 d
  Si4   Si4+   2 i 0.9945(4) 0.1883(4) 0.7047(3) 1.  0 d
  O1    O2-    1 h 0.5 0.5 0.5 1.  0 d
  O2    O2-    2 i 0.700(2) 0.219(1) 0.0099(7) 1.  0 d
  O3    O2-    2 i 0.862(1) 0.265(1) 0.5714(7) 1.  0 d
  O4    O2-    2 i 0.545(1) 0.153(1) 0.5832(7) 1.  0 d
  O5    O2-    2 i 0.872(1) 0.3003(9) 0.8011(7) 1.  0 d
  O6    O2-    2 i 0.194(1) 0.253(1) 0.6769(7) 1.  0 d
  O7    O2-    2 i 0.952(1) 0.030(1) 0.2415(7) 1.  0 d
  O8    O2-    2 i 0.562(1) 0.550(1) 0.8512(7) 1.  0 d
  O9    O2-    2 i 0.146(1) 0.597(1) 0.8478(7) 1.  0 d
  O10   O2-    2 i 0.533(1) 0.067(1) 0.2195(7) 1.  0 d
  O11   O2-    2 i 0.482(1) 0.750(1) 0.2020(7) 1.  0 d
  O12   O2-    2 i 0.317(1) 0.739(1) 0.6341(7) 1.  0 d
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_22
_atom_site_aniso_U_23
_atom_site_aniso_U_33
  Cs1   0.0140(3) -0.0047(2) 0.0001(2) 0.0225(3) 0.0028(2) 0.0147(3)
  Cs2   0.0162(3) -0.0066(2) 0.0011(2) 0.0230(3) -0.0042(2) 0.0164(3)
  Nb1   0.0068(3) -0.0027(2) 0.0010(2) 0.0065(3) -0.0014(3) 0.0066(3)
  Si1   0.008(1) -0.0017(8) 0.0008(9) 0.007(1) -0.0026(9) 0.008(1)
  Si2   0.005(1) -0.0029(8) 0.0004(9) 0.011(1) -0.0015(9) 0.007(1)
  Si3   0.007(2) -0.0029(8) 0.0018(9) 0.011(1) -0.0032(9) 0.008(1)
  Si4   0.006(1) -0.0009(8) 0.0004(9) 0.008(1) -0.0010(9) 0.008(1)
_refine_ls_R_factor_all            0.03