data_2019712
_publ_section_title
;
 Hexabromo- and hexaiododisilane: small and simple molecules showing
 completely different crystal structures
;
_journal_coeditor_code           QS3044
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1088
_journal_page_last               1091
_journal_paper_doi               10.1107/S2053229614022992
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'I6 Si2'
_chemical_formula_moiety         'I6 Si2'
_chemical_formula_sum            'I6 Si2'
_chemical_formula_weight         817.58
_chemical_name_systematic
;
hexaiododisilane
;
_space_group_IT_number           148
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3'
_symmetry_space_group_name_H-M   'R -3 :H'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   7.1436(9)
_cell_length_b                   7.1436(9)
_cell_length_c                   22.213(3)
_cell_measurement_reflns_used    1398
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.7
_cell_measurement_theta_min      3.4
_cell_volume                     981.7(2)
_computing_cell_refinement
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_collection
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_reduction
;
X-AREA (Stoe & Cie, 2001)
;
_computing_molecular_graphics
;
XP (Sheldrick, 2008)
;
_computing_publication_material
;
SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 2008)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Stoe IPDS II two-circle'
_diffrn_measurement_method       ω
_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  0.0532
_diffrn_reflns_av_sigmaI/netI    0.0394
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            1409
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.43
_diffrn_reflns_theta_min         3.42
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    14.363
_exptl_absorpt_correction_T_max  0.1524
_exptl_absorpt_correction_T_min  0.1442
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
[MULABS (Spek, 2009; Blessing, 1995)]
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    4.149
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1038
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.21
_refine_diff_density_max         1.456
_refine_diff_density_min         -1.571
_refine_ls_extinction_coef       0.0055(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_extinction_method
;
SHELXL97 (Sheldrick, 2008)
;
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_matrix_type           full
_refine_ls_number_parameters     14
_refine_ls_number_reflns         500
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0510
_refine_ls_R_factor_gt           0.0470
_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/[σ²(Fo²)+(0.0824P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1211
_refine_ls_wR_factor_ref         0.1234
_reflns_number_gt                438
_reflns_number_total             500
_reflns_threshold_expression     I>2σ(I)
_iucr_refine_instructions_details
;
TITL au116 in R-3
CELL  0.71073     7.1436   7.1436  22.213   90.000  90.000 120.000
ZERR  3           0.0009   0.0009   0.003    0.000   0.000   0.000
LATT   3
SYMM             - Y ,          X - Y ,              Z
SYMM         - X + Y ,            - X ,              Z
SFAC  I  Si
UNIT  18 6
TEMP-100
SIZE.22 .22 .21
REM colourless block
L.S. 10
FMAP 2
PLAN 10
ACTA50
BOND $H
CONF
WGHT    0.082400
EXTI    0.005547
FVAR       0.64143
I1    1    0.320287    0.326220    0.085778    11.00000    0.03429    0.03419 =
         0.04341   -0.00505   -0.00568    0.01274
SI1   2    0.000000    0.000000    0.052519    10.33333    0.02865    0.02865 =
         0.02653    0.00000    0.00000    0.01433
HKLF 4
;
_[local]_cod_data_source_file    qs3044sup1.cif
_[local]_cod_data_source_block   au116
_[local]_cod_cif_authors_sg_H-M  R-3
_cod_depositor_comments
'Adding full bibliography for 2019711--2019712.cif.'
_cod_original_cell_volume        981.70(10)
_cod_database_code               2019712
_cod_database_fobs_code          2019712
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'x+2/3, y+1/3, z+1/3'
'-y+2/3, x-y+1/3, z+1/3'
'-x+y+2/3, -x+1/3, z+1/3'
'x+1/3, y+2/3, z+2/3'
'-y+1/3, x-y+2/3, z+2/3'
'-x+y+1/3, -x+2/3, z+2/3'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'-x+2/3, -y+1/3, -z+1/3'
'y+2/3, -x+y+1/3, -z+1/3'
'x-y+2/3, x+1/3, -z+1/3'
'-x+1/3, -y+2/3, -z+2/3'
'y+1/3, -x+y+2/3, -z+2/3'
'x-y+1/3, x+2/3, -z+2/3'
loop_
_atom_site_type_symbol
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_occupancy
_atom_site_symmetry_multiplicity
I I1 0.32029(8) 0.32622(6) 0.08578(2) 0.0392(4) Uani d . 1 1
Si Si1 0.0000 0.0000 0.05252(10) 0.0279(7) Uani d S 1 3
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
I1 0.0343(4) 0.0342(4) 0.0434(6) 0.0127(2) -0.00568(13) -0.00505(12)
Si1 0.0287(9) 0.0287(9) 0.0265(12) 0.0143(4) 0.000 0.000
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
I I -0.4742 1.8119 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Si Si 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle
Si1 Si1 I1 10 2 107.74(5)
Si1 Si1 I1 10 . 107.74(5)
I1 Si1 I1 2 . 111.15(5)
Si1 Si1 I1 10 3 107.74(5)
I1 Si1 I1 2 3 111.15(5)
I1 Si1 I1 . 3 111.15(5)
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
I1 Si1 . 2.4248(8)
Si1 Si1 10 2.333(5)
Si1 I1 2 2.4247(8)
Si1 I1 3 2.4248(8)
