Synthesis and Characterization of Open-Framework Niobium Silicates: Rb2(Nb2O4)(Si2O6).H2O and the Dehydrated Phase Rb2(Nb2O4)(Si2O6)
Jhen-Ming Tasi; Po-Tao Tu; Ting-Shan Chan; Kwang-Hwa Lii; Inorganic Chemistry 47 (2008) 11223–11227; doi:10.1021/ic801525d

data_4306702
_publ_contact_author
;
Kwang-Hwa Lii
Department of Chemistry
National Central University
Jhongli, Taiwan 320
;
_publ_contact_author_email
;
liikh@cc.ncu.edu.tw
;
_publ_section_title
;
Synthesis and Characterization of Open-Framework Niobium Silicates:
Rb2(Nb2O4)(Si2O6).H2O and the Dehydrated Phase Rb2(Nb2O4)(Si2O6)
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              11223
_journal_page_last               11227
_journal_paper_doi               10.1021/ic801525d
_journal_volume                  47
_journal_year                    2008
_chemical_formula_moiety         Rb2(Nb2O4)(Si2O6)
_chemical_formula_sum            'Nb2 O10 Rb2 Si2'
_chemical_formula_weight         572.94
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           80
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'I 4bw'
_symmetry_space_group_name_H-M   'I 41'
_atom_sites_solution_hydrogens   -
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            16
_cell_length_a                   10.2395(6)
_cell_length_b                   10.2395(6)
_cell_length_c                   38.832(3)
_cell_measurement_temperature    296(2)
_cell_volume                     4071.4(5)
_computing_cell_refinement       'Bruker Smart'
_computing_data_collection       'Bruker Smart'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    Diamond
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0202
_diffrn_reflns_av_sigmaI/netI    0.0301
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       46
_diffrn_reflns_limit_l_min       -51
_diffrn_reflns_number            8935
_diffrn_reflns_theta_full        28.40
_diffrn_reflns_theta_max         28.40
_diffrn_reflns_theta_min         2.06
_exptl_absorpt_coefficient_mu    12.027
_exptl_absorpt_correction_T_max  0.949
_exptl_absorpt_correction_T_min  0.823
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.739
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             4224
_exptl_crystal_size_max          0.112
_exptl_crystal_size_mid          0.112
_exptl_crystal_size_min          0.062
_refine_diff_density_max         1.749
_refine_diff_density_min         -1.528
_refine_diff_density_rms         0.129
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.510(12)
_refine_ls_extinction_coef       0.000131(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    -
_refine_ls_matrix_type           full
_refine_ls_number_parameters     299
_refine_ls_number_reflns         4811
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0322
_refine_ls_R_factor_gt           0.0272
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0196P)^2^+21.4298P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0590
_refine_ls_wR_factor_ref         0.0608
_reflns_number_gt                4382
_reflns_number_total             4811
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic801525d_si_002_2.cif
_cod_data_source_block           nb_2
_cod_original_cell_volume        4071.4(4)
_cod_database_code               4306702