para-Octaiodophenylsilsesquioxane, [p-IC6H4SiO(1.5)]8, a nearly perfect nano-building block.
Roll, Mark F.; Asuncion, Michael Z.; Kampf, Jeffrey; Laine, Richard M.; ACS nano 2 (2008) 320–326; doi:10.1021/nn700196d

data_4503887
_publ_section_title
;
 para-Octaiodophenylsilsesquioxane, [p-IC6H4SiO(1.5)]8, a nearly perfect
 nano-building block.
;
_journal_issue                   2
_journal_name_full               'ACS nano'
_journal_page_first              320
_journal_page_last               326
_journal_paper_doi               10.1021/nn700196d
_journal_volume                  2
_journal_year                    2008
_chemical_formula_moiety         'C48 H32 O12 Si8 I8, C4 H8 O2'
_chemical_formula_sum            'C52 H40 I8 O14 Si8'
_chemical_formula_weight         2128.76
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           87
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4'
_symmetry_space_group_name_H-M   'I 4/m'
_atom_sites_solution_hydrogens   constr
_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                   20.0403(11)
_cell_length_b                   20.0403(11)
_cell_length_c                   21.4606(12)
_cell_measurement_reflns_used    6910
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      20.36
_cell_measurement_theta_min      2.88
_cell_volume                     8618.9(8)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0747
_diffrn_reflns_av_sigmaI/netI    0.0349
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            28258
_diffrn_reflns_theta_full        21.12
_diffrn_reflns_theta_max         21.12
_diffrn_reflns_theta_min         2.87
_exptl_absorpt_coefficient_mu    3.035
_exptl_absorpt_correction_T_max  0.7933
_exptl_absorpt_correction_T_min  0.3013
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Blessing, R. Acta Cryst. (1995) A51 33-38'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.641
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             4000
_exptl_crystal_size_max          0.52
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.08
_refine_diff_density_max         2.118
_refine_diff_density_min         -1.303
_refine_diff_density_rms         0.169
_refine_ls_extinction_coef       0.00012(3)
_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   1.134
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     193
_refine_ls_number_reflns         2399
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.134
_refine_ls_R_factor_all          0.0915
_refine_ls_R_factor_gt           0.0740
_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^)+(0.1310P)^2^+145.9531P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2186
_refine_ls_wR_factor_ref         0.2302
_reflns_number_gt                1861
_reflns_number_total             2399
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            nn700196d-file004.cif
_cod_data_source_block           8i3
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Tetragonal' changed to 'tetragonal'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      I4/m
_cod_database_code               4503887