A new polymorph of 2,5-bis(4-pyridyl)-1,3,4-thiadiazole
Zhao, Xiao-Jun; Cai, Hua; Du, Miao; Acta Crystallographica Section E 61 (2005) o2547–o2548; doi:10.1107/S1600536805022142

data_2206594
_publ_section_title
;
 A new polymorph of 2,5-bis(4-pyridyl)-1,3,4-thiadiazole
;
_journal_coeditor_code           WW6408
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2547
_journal_page_last               o2548
_journal_paper_doi               10.1107/S1600536805022142
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C12 H8 N4 S'
_chemical_formula_moiety         'C12 H8 N4 S'
_chemical_formula_sum            'C12 H8 N4 S'
_chemical_formula_weight         240.28
_chemical_name_systematic
;
2,5-bis(4-pyridyl)-1,3,4-thiadiazole
;
_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 104.948(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.395(2)
_cell_length_b                   7.1833(11)
_cell_length_c                   11.4151(18)
_cell_measurement_reflns_used    1940
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.32
_cell_measurement_theta_min      3.24
_cell_volume                     1061.2(3)
_computing_cell_refinement       APEX-II
_computing_data_collection       'APEX-II (Bruker, 2003)'
_computing_data_reduction        'SAINT (Bruker, 2001)'
_computing_molecular_graphics    'SHELXTL (Bruker, 2001)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX-II CCD area-detector'
_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  0.0227
_diffrn_reflns_av_sigmaI/netI    0.0262
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       4
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            5414
_diffrn_reflns_theta_full        25.02
_diffrn_reflns_theta_max         25.02
_diffrn_reflns_theta_min         3.15
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.284
_exptl_absorpt_correction_T_max  1.000000
_exptl_absorpt_correction_T_min  0.770069
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.504
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       lamellar
_exptl_crystal_F_000             496
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.226
_refine_diff_density_min         -0.222
_refine_ls_extinction_coef       0.009(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.073
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_refine_ls_matrix_type           full
_refine_ls_number_parameters     155
_refine_ls_number_reflns         1862
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.073
_refine_ls_R_factor_all          0.0406
_refine_ls_R_factor_gt           0.0323
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0679P)^2^+0.0172P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0969
_refine_ls_wR_factor_ref         0.1015
_reflns_number_gt                1515
_reflns_number_total             1862
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ww6408.cif
_cod_data_source_block           I
_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 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2206594
_cod_database_fobs_code          2206594