Refinement of obverse/reverse twins
Herbst-Irmer, Regine; Sheldrick, George M.; Acta Crystallographica, Section B: Structural Science 58 (2002) 477–481; doi:10.1107/S0108768102001039

data_2103123
_publ_section_title
;
 Refinement of obverse/reverse twins
;
_journal_coden_ASTM              ASBSDK
_journal_issue                   3
_journal_name_full
;
 Acta Crystallographica, Section B: Structural Science
;
_journal_page_first              477
_journal_page_last               481
_journal_paper_doi               10.1107/S0108768102001039
_journal_volume                  58
_journal_year                    2002
_chemical_formula_sum            'C24 H54 O3 Si3'
_chemical_formula_weight         474.94
_space_group_IT_number           167
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   10.0793(7)
_cell_length_b                   10.0793(7)
_cell_length_c                   48.409(4)
_cell_measurement_reflns_used    849
_cell_measurement_temperature    133(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      2.5
_cell_volume                     4259.1(6)
_computing_cell_refinement       'Siemens SAINT (V. 4.050, Siemens 1996)'
_computing_data_collection       'Siemens SMART (V. 4.202, Siemens 1996)'
_computing_data_reduction        'Siemens SAINT (V. 4.050, Siemens 1996)'
_computing_molecular_graphics    'Bruker AXS SHELXTL (V. 5.10)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      133(2)
_diffrn_detector_area_resol_mean '8.192 pixels/mm'
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Stoe-Siemens-Huber four circle diffractometer'
_diffrn_measurement_method       'phi scan'
_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  0.037
_diffrn_reflns_av_sigmaI/netI    0.0203
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       57
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            47973
_diffrn_reflns_theta_full        25.17
_diffrn_reflns_theta_max         25.17
_diffrn_reflns_theta_min         2.48
_exptl_absorpt_coefficient_mu    0.188
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_density_diffrn    1.111
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1584
_refine_diff_density_max         0.388
_refine_diff_density_min         -0.333
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.111
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     51
_refine_ls_number_reflns         849
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.111
_refine_ls_R_factor_all          0.0425
_refine_ls_R_factor_gt           0.0349
_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^)+(0.0527P)^2^+2.7315P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0875
_refine_ls_wR_factor_ref         0.0903
_reflns_number_gt                751
_reflns_number_total             849
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jz0014.cif
_cod_original_sg_symbol_H-M      R-3c
_cod_database_code               2103123