Molecular structure of 1,1,2,2-tetra-tert-butyldisilane: unusual structural motifs in sterically crowded disilanes.
Hinchley, Sarah L.; Robertson, Heather E.; Parkin, Andrew; Rankin, David W. H.; Tekautz, Günther; Hassler, Karl; Dalton transactions (Cambridge, England : 2003)  (2004) 759–766; doi:10.1039/b316701a

data_7013967
_publ_section_title
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 Molecular structure of 1,1,2,2-tetra-tert-butyldisilane: unusual
 structural motifs in sterically crowded disilanes.
;
_journal_issue                   5
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              759
_journal_page_last               766
_journal_paper_doi               10.1039/b316701a
_journal_year                    2004
_chemical_formula_moiety         'tBu2 SiH SiH tBu2'
_chemical_formula_sum            'C16 H38 Si2'
_chemical_formula_weight         286.64
_chemical_name_systematic
;
?
;
_space_group_IT_number           62
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2n'
_symmetry_space_group_name_H-M   'P n m a'
_atom_sites_solution_hydrogens   geometric/difmap
_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                   9.4428(8)
_cell_length_b                   12.8854(11)
_cell_length_c                   16.5058(13)
_cell_measurement_reflns_used    3023
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      26.5
_cell_measurement_theta_min      2.4
_cell_volume                     2008.3(3)
_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  'SHELXTL '
_computing_structure_solution    'SHELXTL '
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART APEX 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  0.0399
_diffrn_reflns_av_sigmaI/netI    0.0316
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            10755
_diffrn_reflns_theta_full        26.39
_diffrn_reflns_theta_max         26.39
_diffrn_reflns_theta_min         2.01
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.165
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.797
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    0.948
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cylinder
_exptl_crystal_F_000             648
_exptl_crystal_size_max          1.00
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.309
_refine_diff_density_min         -0.285
_refine_diff_density_rms         0.049
_refine_ls_extinction_coef       0
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.079
_refine_ls_hydrogen_treatment    'riding, rotating and restrained'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     146
_refine_ls_number_reflns         2141
_refine_ls_number_restraints     25
_refine_ls_restrained_S_all      1.082
_refine_ls_R_factor_all          0.0815
_refine_ls_R_factor_gt           0.0646
_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^)+(0.0719P)^2^+0.9764P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1520
_refine_ls_wR_factor_ref         0.1616
_reflns_number_gt                1672
_reflns_number_total             2141
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b316701a.txt
_cod_data_source_block           sibu4b
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
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 
;
_cod_original_sg_symbol_H-M      Pnma
_cod_database_code               7013967