Variable-temperature neutron diffraction studies of the short, strong hydrogen bonds in the crystal structure of pyridine-3,5-dicarboxylic acid
Cowan, John. A.; Howard, Judith A. K.; McIntyre, Garry, J.; Lo, Samuel M.-F; Williams, Ian D.; Acta Crystallographica Section B 61 (2005) 724–730; doi:10.1107/S0108768105030077

data_2100305
_publ_section_title
;
 Variable-temperature neutron diffraction studies of the short, strong
 hydrogen bonds in the crystal structure of pyridine-3,5-dicarboxylic
 acid
;
_journal_coeditor_code           BS5020
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              724
_journal_page_last               730
_journal_paper_doi               10.1107/S0108768105030077
_journal_volume                  61
_journal_year                    2005
_chemical_formula_moiety         'C7 H3 D2 N O4'
_chemical_formula_sum            'C7 H3 D2 N O4'
_chemical_formula_weight         169.0
_chemical_name_common            'Dinicotinic Acid'
_chemical_name_systematic
;
 Pyridine-3,5-dicarboxylic acid
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 108.304(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.7614(13)
_cell_length_b                   11.2243(17)
_cell_length_c                   6.6430(13)
_cell_measurement_reflns_used    815
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      34.91
_cell_measurement_theta_min      3.63
_cell_volume                     691.0(2)
_computing_cell_refinement       'RAFD9 (Filhol, 1998)'
_computing_data_collection       'MAD and HKLGEN (Barthelemy, 1984)'
_computing_data_reduction        'RACER (Wilkinson, et al. 1988)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.824
_diffrn_measured_fraction_theta_max 0.824
_diffrn_measurement_device_type  D9
_diffrn_measurement_method       'theta - two theta scans'
_diffrn_radiation_monochromator  'Copper (2 2 0)'
_diffrn_radiation_probe          neutron
_diffrn_radiation_source         'ILL high flux reactor'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.84060(10)
_diffrn_reflns_av_R_equivalents  0.0141
_diffrn_reflns_av_sigmaI/netI    0.0468
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            1677
_diffrn_reflns_theta_full        34.85
_diffrn_reflns_theta_max         34.85
_diffrn_reflns_theta_min         3.37
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 50
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.054
_exptl_absorpt_correction_T_max  0.9569
_exptl_absorpt_correction_T_min  0.9148
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details   'DATAP, (Coppens, 1979)'
_exptl_crystal_colour            'pale brown'
_exptl_crystal_density_diffrn    1.610
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             255
_exptl_crystal_size_max          2.7
_exptl_crystal_size_mid          1.5
_exptl_crystal_size_min          0.9
_refine_diff_density_max         0.731
_refine_diff_density_min         -0.624
_refine_ls_extinction_coef       0.017(2)
_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   1.617
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     156
_refine_ls_number_reflns         1503
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.617
_refine_ls_R_factor_all          0.0967
_refine_ls_R_factor_gt           0.0738
_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^)+(0.0500P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1456
_refine_ls_wR_factor_ref         0.1530
_reflns_number_gt                1182
_reflns_number_total             1503
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bs5020.cif
_cod_data_source_block           dad
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        691.02(19)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2100305
_cod_database_fobs_code          2100305