2,5-Diamino-3,6-dichloropyrazine
Barclay, Tosha M.; Cordes, A. Wallace; Oakley, Richard T.; Preuss, Kathryn E.; Zhang, Hongzhou; Acta Crystallographica Section C 54 (1998) 1018–1019; doi:10.1107/S0108270198001152

data_2007436
_publ_section_title
;
 2,5-Diamino-3,6-dichloropyrazine
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1018
_journal_page_last               1019
_journal_paper_doi               10.1107/S0108270198001152
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'C4 H4 Cl2 N4 '
_chemical_formula_sum            'C4 H4 Cl2 N4'
_chemical_formula_weight         179.01
_chemical_name_systematic
;
 2,5-diamino-dichloropyrazine
;
_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                90.0
_cell_angle_beta                 101.162(8)
_cell_angle_gamma                90.0
_cell_formula_units_Z            2
_cell_length_a                   3.7582(4)
_cell_length_b                   14.5505(15)
_cell_length_c                   6.2451(6)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      15.00
_cell_measurement_theta_min      12.00
_cell_volume                     335.05(6)
_computing_cell_refinement       'CAD-4/PC Software'
_computing_data_collection       'CAD-4/PC Software (Enraf--Nonius, 1994)'
_computing_data_reduction        'DATRD2 in NRCVAX (Gabe et al., 1989)'
_computing_molecular_graphics    NRCVAX
_computing_publication_material  NRCVAX
_computing_structure_refinement  NRCVAX
_computing_structure_solution    NRCVAX
_diffrn_ambient_temperature      293
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       '\q/2\q scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'xray tube'
_diffrn_radiation_type           'Molybdenum K\a'
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.026
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1617
_diffrn_reflns_theta_max         27.40
_diffrn_reflns_theta_min         0.00
_diffrn_standards_decay_%        2.0
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.89
_exptl_absorpt_correction_T_max  0.813
_exptl_absorpt_correction_T_min  0.754
_exptl_absorpt_correction_type   'analytical (ABSORB; Gabe et al., 1989)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.774
_exptl_crystal_density_meas      ?
_exptl_crystal_description       block
_exptl_crystal_F_000             180.6
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.26
_refine_diff_density_min         -0.25
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_obs   1.08
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     54
_refine_ls_number_reflns         757
_refine_ls_R_factor_all          0.033
_refine_ls_R_factor_obs          .033
_refine_ls_shift/esd_max         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     'w = 1/[\s^2^(F)+0.0025F^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.063
_refine_ls_wR_factor_obs         .063
_reflns_number_observed          765
_reflns_number_total             765
_reflns_observed_criterion       'Inet > 0'
_cod_data_source_file            fr1107.cif
_cod_data_source_block           fr1107
_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:

'_atom_site_thermal_displace_type' tag value 'Uij' was replaced with
'Uani' value 5 times.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z 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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 1/[\s^2^(F)+0.0025F^2^]' 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)+0.0025F^2^]'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_original_formula_sum        'C4 H4 Cl2 N4 '
_cod_database_code               2007436
_cod_database_fobs_code          2007436