Two Cyclotetrasiloxanes at 143K
Hensen, Karl; Gebhardt, Frank; Kettner, Markus; Pickel, Peter; Bolte, Michael; Acta Crystallographica Section C 53 (1997) 1867–1869; doi:10.1107/S0108270197010068

data_2006837
_publ_section_title
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 Two Cyclotetrasiloxanes at 143K
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1867
_journal_page_last               1869
_journal_paper_doi               10.1107/S0108270197010068
_journal_volume                  53
_journal_year                    1997
_chemical_formula_sum            'C48 H40 O4 Si4'
_chemical_formula_weight         793.16
_chemical_name_systematic
;
octaphenylcyclotetrasiloxane
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_audit_creation_method           SHELXL
_cell_angle_alpha                83.3230(10)
_cell_angle_beta                 83.7350(10)
_cell_angle_gamma                76.0300(10)
_cell_formula_units_Z            2
_cell_length_a                   10.66880(10)
_cell_length_b                   10.73530(10)
_cell_length_c                   18.8291(2)
_cell_measurement_reflns_used    7927
_cell_measurement_temperature    143
_cell_measurement_theta_max      25.00
_cell_measurement_theta_min      1.00
_cell_volume                     2071.21(4)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        'SAINT (Siemens, 1995)'
_computing_molecular_graphics    'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_structure_refinement  'SHELXL96 (Sheldrick, 1996b)'
_computing_structure_solution    'SHELXS96 (Sheldrick, 1990)'
_diffrn_ambient_temperature      143
_diffrn_measurement_device       'Siemens CCD three-circle diffractometer'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  'highly oriented graphite crystal'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0176
_diffrn_reflns_av_sigmaI/netI    0.0167
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            32949
_diffrn_reflns_theta_max         26.40
_diffrn_reflns_theta_min         1.96
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  720
_diffrn_standards_number         501
_exptl_absorpt_coefficient_mu    0.188
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.847
_exptl_absorpt_correction_type   'Empirical (SADABS; Sheldrick, 1996a)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.272
_exptl_crystal_description       block
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.60
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.356
_refine_diff_density_min         -0.255
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.031
_refine_ls_goodness_of_fit_obs   1.056
_refine_ls_hydrogen_treatment    'H atoms: see text'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     505
_refine_ls_number_reflns         8383
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_restrained_S_obs      1.056
_refine_ls_R_factor_all          0.0375
_refine_ls_R_factor_obs          .0301
_refine_ls_shift/esd_max         0.001
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.9123P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0825
_refine_ls_wR_factor_obs         .0784
_reflns_number_observed          7270
_reflns_number_total             8383
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            jz1227.cif
_cod_data_source_block           I
_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_enum 1527 2010-12-29 10:47:43Z saulius 

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:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.9123P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.9123P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
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_cod_database_code               2006837