octakis(Isobutyl)octasilsesquioxane
MacKinnon, I. A.; Liu, Z.; Taylor, P. G.; Yang, Y.; Hursthouse, Michael B.; Horton, Peter N.; Light, Mark E.; Bassindale, A. R.; Crystal Structure Report Archive  (2001) 59–; doi:

data_1519294
_publ_section_title
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 octakis(Isobutyl)octasilsesquioxane
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_journal_name_full               'Crystal Structure Report Archive'
_journal_page_first              59
_journal_year                    2001
_chemical_formula_sum            'C16 H36 O6 Si4'
_chemical_formula_weight         436.81
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                96.541(8)
_cell_angle_beta                 91.269(7)
_cell_angle_gamma                99.439(7)
_cell_formula_units_Z            2
_cell_length_a                   9.9881(13)
_cell_length_b                   10.8183(14)
_cell_length_c                   10.9540(18)
_cell_measurement_reflns_used    21077
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.91
_cell_volume                     1159.0(3)
_computing_cell_refinement       'DENZO & COLLECT'
_computing_data_collection
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, 1998)'
_computing_data_reduction        'DENZO & COLLECT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.960
_diffrn_measured_fraction_theta_max 0.960
_diffrn_measurement_device_type  'Bruker-Nonius KappaCCD'
_diffrn_measurement_method       '\F & \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Bruker-Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.2177
_diffrn_reflns_av_sigmaI/netI    0.2690
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            10942
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         3.05
_exptl_absorpt_coefficient_mu    0.283
_exptl_absorpt_correction_T_max  0.9722
_exptl_absorpt_correction_T_min  0.9722
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SORTAV (Blessing, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.252
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             472
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.445
_refine_diff_density_min         -0.403
_refine_diff_density_rms         0.090
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.968
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     243
_refine_ls_number_reflns         3921
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.968
_refine_ls_R_factor_all          0.2189
_refine_ls_R_factor_gt           0.0841
_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^)+(0.0533P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1572
_refine_ls_wR_factor_ref         0.2024
_reflns_number_gt                1619
_reflns_number_total             3921
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            eCrystal-59.cif
_cod_data_source_block           01src993
_cod_depositor_comments
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Citation :
MacKinnon, I. A. and Liu, Z. and Taylor, P. G. and Yang, Y. and 
Hursthouse, Michael B. and Horton, Peter N. and Light, Mark E. and 
Bassindale, A. R. (2001) 
University of Southampton, Crystal Structure Report Archive. 
(doi:10.5258/ecrystals/59)

More at:
http://ecrystals.chem.soton.ac.uk/59/
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_cod_original_sg_symbol_H-M      P-1
_cod_database_code               1519294