1,1'-Dimethyl-4,5'-dinitro-2,2'-biimidazole, C~8~H~8~N~6~O~4~
Casas, J. S.; Castiñeiras, A.; Martínez, G.; Sordo, J.; Varela, J. M.; Acta Crystallographica Section C 51 (1995) 1414–1416; doi:10.1107/S0108270194014915

data_2003665
_publ_section_title
;
 1,1'-Dimethyl-4,5'-dinitro-2,2'-biimidazole, C~8~H~8~N~6~O~4~
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1414
_journal_page_last               1416
_journal_paper_doi               10.1107/S0108270194014915
_journal_volume                  51
_journal_year                    1995
_chemical_compound_source
;Single crystals were obtained by slow evaporation of an
aqueous ethanol solution.
;
_chemical_formula_moiety         'C8 H8 N6 O4'
_chemical_formula_sum            'C8 H8 N6 O4'
_chemical_formula_weight         252.19
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90.
_cell_angle_beta                 109.54(1)
_cell_angle_gamma                90.
_cell_formula_units_Z            4
_cell_length_a                   10.809(2)
_cell_length_b                   9.581(2)
_cell_length_c                   10.986(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      13.2
_cell_measurement_theta_min      5.5
_cell_volume                     1072.2(4)
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \w-2\q
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.030
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            3439
_diffrn_reflns_theta_max         30
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.12
_exptl_absorpt_correction_T_max  1.039
_exptl_absorpt_correction_T_min  0.986
_exptl_absorpt_correction_type   'empirical, \y scan (Walker & Stuart, 1983)'
_exptl_crystal_colour            amber
_exptl_crystal_density_diffrn    1.562
_exptl_crystal_description       prismatic
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.18
_refine_diff_density_min         -0.23
_refine_ls_extinction_coef       9.84E-8
_refine_ls_extinction_method     'Zachariasen (1963)'
_refine_ls_goodness_of_fit_obs   1.11
_refine_ls_hydrogen_treatment    noref
_refine_ls_number_parameters     164
_refine_ls_number_reflns         876
_refine_ls_R_factor_obs          0.0515
_refine_ls_shift/esd_max         0.001
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/[\s^2^(F)]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.0524
_reflns_number_observed          876
_reflns_number_total             3135
_reflns_observed_criterion       I>3\s(I)
_cod_data_source_file            hr1036.cif
_cod_data_source_block           hr1036a
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 1/[\s^2^(F)]' 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^(F)]'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1072.1(6)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2003665