1<i>H</i>-Benzimidazol-3-ium-2-carboxylate dihydrate
Yao, Xing-Jun; Yuan, Qian; Acta Crystallographica Section E 67 (2011) o1399–; doi:10.1107/S1600536811017399

data_2230278
_publ_section_title
;
 1<i>H</i>-Benzimidazol-3-ium-2-carboxylate dihydrate
;
_journal_coeditor_code           CV5086
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1399
_journal_paper_doi               10.1107/S1600536811017399
_journal_volume                  67
_journal_year                    2011
_chemical_formula_iupac          'C8 H6 N2 O2, 2H2 O'
_chemical_formula_moiety         'C8 H6 N2 O2, 2(H2 O)'
_chemical_formula_sum            'C8 H10 N2 O4'
_chemical_formula_weight         198.18
_chemical_name_systematic
;
1<i>H</i>-Benzimidazol-3-ium-2-carboxylate dihydrate
;
_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_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 109.728(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.8503(15)
_cell_length_b                   7.3679(17)
_cell_length_c                   18.939(4)
_cell_measurement_reflns_used    1540
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      26.23
_cell_measurement_theta_min      2.28
_cell_volume                     899.8(3)
_computing_cell_refinement       '<i>SAINT</i> (Bruker, 2005)'
_computing_data_collection       '<i>APEX2</i> (Bruker, 2005)'
_computing_data_reduction        '<i>SAINT</i> (Bruker, 2005)'
_computing_molecular_graphics    '<i>SHELXTL</i> (Sheldrick, 2008)'
_computing_publication_material  '<i>SHELXTL</i> (Sheldrick, 2008)'
_computing_structure_refinement  '<i>SHELXTL</i> (Sheldrick, 2008)'
_computing_structure_solution    '<i>SHELXTL</i> (Sheldrick, 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEXII CCD'
_diffrn_measurement_method       '\f and \w'
_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  0.0952
_diffrn_reflns_av_sigmaI/netI    0.0762
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            4496
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.28
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.119
_exptl_absorpt_correction_T_max  0.9596
_exptl_absorpt_correction_T_min  0.9518
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(<i>SADABS</i>; Bruker, 2005)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.463
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             416
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.38
_exptl_crystal_size_min          0.35
_refine_diff_density_max         0.181
_refine_diff_density_min         -0.157
_refine_ls_extinction_coef       0.097(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     '<i>SHELXTL</i> (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     128
_refine_ls_number_reflns         1760
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0551
_refine_ls_R_factor_gt           0.0431
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0410P)^2^+0.0001P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1044
_refine_ls_wR_factor_ref         0.1108
_reflns_number_gt                1342
_reflns_number_total             1760
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            cv5086.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2230278
_cod_database_fobs_code          2230278