Icosaniobate: A New Member of the Isoniobate Family
Maekawa, Masaki; Ozawa, Yoshiki; Yagasaki, Atsushi; Inorganic Chemistry 45 (2006) 9608–9609; doi:10.1021/ic0601788

data_4332274
_publ_section_title
;
 Icosaniobate:&#x00A0; A New Member of the Isoniobate Family
;
_journal_issue                   24
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              9608
_journal_page_last               9609
_journal_paper_doi               10.1021/ic0601788
_journal_volume                  45
_journal_year                    2006
_chemical_formula_sum            'C128 H288 N8 Nb20 O54'
_chemical_formula_weight         4661.86
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           18
_symmetry_space_group_name_Hall  'P 2bc 2'
_symmetry_space_group_name_H-M   'P 2 21 21'
_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            4
_cell_length_a                   17.7284(18)
_cell_length_b                   33.542(3)
_cell_length_c                   34.316(2)
_cell_measurement_temperature    150(1)
_cell_volume                     20406(3)
_computing_data_collection       'RAPID AUTO'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(1)
_diffrn_detector_area_resol_mean 10
_diffrn_measured_fraction_theta_full .986
_diffrn_measured_fraction_theta_max .986
_diffrn_measurement_device_type  'Rigaku R-axis Rapid diffractometer'
_diffrn_measurement_method       '\w-axis rotation'
_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  0.0453
_diffrn_reflns_av_sigmaI/netI    0.0270
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       43
_diffrn_reflns_limit_k_min       -43
_diffrn_reflns_limit_l_max       44
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            327009
_diffrn_reflns_theta_full        27.43
_diffrn_reflns_theta_max         27.43
_diffrn_reflns_theta_min         2.99
_exptl_absorpt_coefficient_mu    1.140
_exptl_absorpt_correction_T_max  0.6910
_exptl_absorpt_correction_T_min  0.6279
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.517
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             9456
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.35
_refine_diff_density_max         2.046
_refine_diff_density_min         -.845
_refine_diff_density_rms         .152
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.08(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.080
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1922
_refine_ls_number_reflns         45939
_refine_ls_number_restraints     48
_refine_ls_restrained_S_all      1.082
_refine_ls_R_factor_all          0.0640
_refine_ls_R_factor_gt           0.0611
_refine_ls_shift/su_max          0.724
_refine_ls_shift/su_mean         0.008
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0985P)^2^+72.1941P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1758
_refine_ls_wR_factor_ref         0.1780
_reflns_number_gt                43336
_reflns_number_total             45939
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic0601788sup1.cif
_cod_data_source_block           ya0504-51
_cod_database_code               4332274