Crystal structure of bis[(4R*,5R*)2-amino-4,5-trans-dihydroxy-1,3-dimethoxy-4,5-dihydroimidazolium] hexafluorosilicate, [C5H12N3O4]2[SiF6]
Alexander Schwärzler; Klaus Wurst; Gerhard Laus; Ulrich J. Griesser; Günther Bonn; Herwig Schottenberger; Zeitschrift für Kristallographie - New Crystal Structures 224 (2009) 409–; doi:

data_8102454
_publ_section_title
;
 Crystal structure of
 bis[(4R*,5R*)2-amino-4,5-trans-dihydroxy-1,3-dimethoxy-4,5-dihydroimidazolium]
 hexafluorosilicate, [C5H12N3O4]2[SiF6]
;
_journal_issue                   3
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              409
_journal_volume                  224
_journal_year                    2009
_chemical_formula_sum            'C10 H24 F6 N6 O8 Si'
_chemical_formula_weight         498.44
_space_group_IT_number           86
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-P 4bc'
_symmetry_space_group_name_H-M   'P 42/n :2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   15.6460(10)
_cell_length_b                   15.6460(10)
_cell_length_c                   8.2024(5)
_cell_measurement_reflns_used    12119
_cell_measurement_temperature    233(2)
_cell_measurement_theta_max      23.1
_cell_measurement_theta_min      1.0
_cell_volume                     2007.9(2)
_computing_data_collection       COLLECT
_computing_data_reduction        'DENZO and SCALEPACK'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      233(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Nonius KappaCCD'
_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  0.1200
_diffrn_reflns_av_sigmaI/netI    0.0598
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            9279
_diffrn_reflns_theta_full        23.1
_diffrn_reflns_theta_max         23.1
_diffrn_reflns_theta_min         1.84
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.224
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.649
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1032
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.215
_refine_diff_density_min         -0.230
_refine_diff_density_rms         0.057
_refine_ls_extinction_coef       0.0050(11)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     159
_refine_ls_number_reflns         1396
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.054
_refine_ls_R_factor_all          0.0829
_refine_ls_R_factor_gt           0.0519
_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^)+(0.0438P)^2^+2.1688P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1058
_refine_ls_wR_factor_ref         0.1173
_reflns_number_gt                995
_reflns_number_total             1396
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            1267-2632.cff
_cod_data_source_block           as726
_cod_original_sg_symbol_H-M      P42/n
_cod_database_code               8102454