Structural Characterization of POSS Siloxane Dimer and Trimer
Anderson, Stanley E.; Mitchell, Connie; Haddad, Timothy S.; Vij, Ashwani; Schwab, Joseph J.; Bowers, Michael T.; Chemistry of Materials 18 (2006) 1490–; doi:10.1021/cm052589c

data_4001512
_publ_section_title
;
 Structural Characterization of POSS Siloxane Dimer and Trimer
;
_journal_issue                   6
_journal_name_full               'Chemistry of Materials'
_journal_page_first              1490
_journal_paper_doi               10.1021/cm052589c
_journal_volume                  18
_journal_year                    2006
_chemical_formula_sum            'C84 H154 O25 Si16'
_chemical_formula_weight         2013.51
_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                99.598(2)
_cell_angle_beta                 111.0610(10)
_cell_angle_gamma                110.3050(10)
_cell_formula_units_Z            2
_cell_length_a                   16.0442(10)
_cell_length_b                   18.9546(12)
_cell_length_c                   20.9652(14)
_cell_measurement_reflns_used    9520
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.26
_cell_measurement_theta_min      1.10
_cell_volume                     5261.7(6)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.935
_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  0.0312
_diffrn_reflns_av_sigmaI/netI    0.0360
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            62384
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.26
_diffrn_reflns_theta_min         1.10
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.260
_exptl_absorpt_correction_T_max  0.9523
_exptl_absorpt_correction_T_min  0.9077
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   empirical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.271
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Prism
_exptl_crystal_F_000             2164
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.19
_refine_diff_density_max         0.726
_refine_diff_density_min         -0.378
_refine_diff_density_rms         0.069
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1172
_refine_ls_number_reflns         24398
_refine_ls_number_restraints     8
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0459
_refine_ls_R_factor_gt           0.0390
_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^)+(0.0610P)^2^+2.2335P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1059
_refine_ls_wR_factor_ref         0.1112
_reflns_number_gt                20864
_reflns_number_total             24398
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cm052589csi20051123_044138.cif
_cod_data_source_block           timlt
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        5261.6(6)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               4001512