Disorder and pseudo-symmetry in octakis(trivinylsilyl)octasilicate
Slebodnick, Carla; Angel, Ross J.; Hanson, Brian E.; Agaskar, Pradyot A.; Soler, Tatiana; Falvello, Larry R.; Acta Crystallographica Section B 64 (2008) 330–337; doi:10.1107/S0108768108010227

data_2104158
_publ_section_title
;
 Disorder and pseudo-symmetry in octakis(trivinylsilyl)octasilicate
;
_journal_coeditor_code           WS5065
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              330
_journal_page_last               337
_journal_paper_doi               10.1107/S0108768108010227
_journal_volume                  64
_journal_year                    2008
_chemical_formula_moiety         'C48 H72 O20 Si16'
_chemical_formula_sum            'C48 H72 O20 Si16'
_chemical_formula_weight         1418.50
_chemical_name_common            Octakis(trivinylsilyl)octasilicate
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           79
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'I 4'
_symmetry_space_group_name_H-M   'I 4'
_atom_sites_solution_hydrogens   geom
_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            1
_cell_length_a                   15.0040(6)
_cell_length_b                   15.0040(6)
_cell_length_c                   7.9872(5)
_cell_measurement_reflns_used    5539
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      22.64
_cell_measurement_theta_min      1.84
_cell_volume                     1798.08(15)
_computing_cell_refinement       'CrysAlis (Oxford Diffraction)'
_computing_data_collection       'CrysAlis (Oxford Diffraction)'
_computing_data_reduction        'CrysAlis (Oxford Diffraction)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Oxford Diffraction Xcalibur2'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0564
_diffrn_reflns_av_sigmaI/netI    0.0224
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            10423
_diffrn_reflns_theta_full        30.05
_diffrn_reflns_theta_max         30.05
_diffrn_reflns_theta_min         3.84
_diffrn_standards_decay_%        <2%
_diffrn_standards_interval_count 50
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.345
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.311
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             744
_exptl_crystal_size_max          0.160
_exptl_crystal_size_mid          0.156
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.335
_refine_diff_density_min         -0.293
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.232
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     190
_refine_ls_number_reflns         1399
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.232
_refine_ls_R_factor_all          0.0618
_refine_ls_R_factor_gt           0.0614
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0665P)^2^+1.9447P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1518
_refine_ls_wR_factor_ref         0.1520
_reflns_number_gt                1394
_reflns_number_total             1399
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ws5065.cif
_cod_data_source_block           cs511
_cod_database_code               2104158
_cod_database_fobs_code          2104158