2,6-Diphenylpyridine-4-carboxylic acid
Crispini, Alessandra; Neve, Francesco; Acta Crystallographica Section C 58 (2002) o34–o35; doi:10.1107/S0108270101017693

data_2012443
_publ_section_title
;
 2,6-Diphenylpyridine-4-carboxylic acid
;
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o34
_journal_page_last               o35
_journal_paper_doi               10.1107/S0108270101017693
_journal_volume                  58
_journal_year                    2002
_chemical_formula_moiety         'C18 H13 N O2'
_chemical_formula_sum            'C18 H13 N O2'
_chemical_formula_weight         275.29
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 111.229(17)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.524(4)
_cell_length_b                   5.2898(9)
_cell_length_c                   17.021(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      12.86
_cell_measurement_theta_min      7.96
_cell_volume                     1386.8(5)
_computing_cell_refinement       'XPREP (Bruker, 1997)'
_computing_data_collection       'XPREP (Bruker, 1997)'
_computing_data_reduction        'XPREP (Bruker, 1997)'
_computing_molecular_graphics    'XP (Bruker, 1997)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_measured_fraction_theta_full .999
_diffrn_measured_fraction_theta_max .999
_diffrn_measurement_device       'Siemens R3m/V'
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .069
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            2559
_diffrn_reflns_theta_full        25.05
_diffrn_reflns_theta_max         25.05
_diffrn_reflns_theta_min         1.50
_diffrn_standards_decay_%        'no decay, variation 0.5'
_diffrn_standards_interval_time  48
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    .086
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            pale_yellow
_exptl_crystal_density_diffrn    1.32
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             576
_exptl_crystal_size_max          .23
_exptl_crystal_size_mid          .20
_exptl_crystal_size_min          .17
_refine_diff_density_max         .132
_refine_diff_density_min         -.128
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   .872
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     190
_refine_ls_number_reflns         2469
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      .872
_refine_ls_R_factor_all          .1272
_refine_ls_R_factor_gt           .0448
_refine_ls_shift/su_max          .000
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0250P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .0892
_reflns_number_gt                980
_reflns_number_total             2469
_reflns_threshold_expression     'I >2\s(I)'
_cod_data_source_file            na1541.cif
_cod_data_source_block           I
_cod_depositor_comments
;
Automatic conversion scripts had previously changed 
'_atom_site_refinement_flags' tag values 'd' into 'D' as recommended by 
'cif_core.dic' version 2.4.1. However, manual inspection revealed that the 
underlying problem was actually related to a wrong tag names inside the 
atom site loop. The following changes were performed to resolve the problem: 

* '_atom_site_refinement_flags' tag was changed to '_atom_site_calc_flag'
* '_atom_site_calc_flag' tag was changed to '_atom_site_site_symmetry_order'
* '_atom_site_disorder_group' tag was changed to 
  '_atom_site_refinement_flags_posn'

Antanas Vaitkus,
2015-03-19
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2012443
_cod_database_fobs_code          2012443