Cytosinium hydrogen selenite
Takouachet, Radhwane; Benali-Cherif, Rim; Benali-Cherif, Nourredine; Acta Crystallographica Section E 70 (2014) o186–o187; doi:10.1107/S1600536814001275

data_2239038
_publ_section_title
;
 Cytosinium hydrogen selenite
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o186
_journal_page_last               o187
_journal_paper_doi               10.1107/S1600536814001275
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'C4 H6 N3 O +, H Se O3 -'
_chemical_formula_moiety         'C4 H6 N3 O +, H O3 Se -'
_chemical_formula_sum            'C4 H7 N3 O4 Se'
_chemical_formula_weight         240.09
_chemical_name_common
;
Cytosinium hydrogen selenite
;
_chemical_name_systematic
;
6-Amino-2-methylidene-2,3-dihydropyrimidin-1-ium hydrogen selenite
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.0051(3)
_cell_length_b                   8.6342(2)
_cell_length_c                   12.7131(3)
_cell_measurement_reflns_used    5415
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      29.51
_cell_measurement_theta_min      3.75
_cell_volume                     768.93(4)
_computing_cell_refinement
'DENZO and SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Hooft, 1998)'
_computing_data_reduction
'DENZO and SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'Platon (Spek, 2009)'
_computing_publication_material
'SHELXL-2013 (Sheldrick, 2008) and Platon (Spek, 2009)'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2008)'
_computing_structure_solution    'SIR2004 (Burla <i>et al.</i>, 2005)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\w - \q scans'
_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  0.0673
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            4568
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.995
_diffrn_reflns_theta_min         3.746
_exptl_absorpt_coefficient_mu    4.863
_exptl_absorpt_correction_T_max  0.3690
_exptl_absorpt_correction_T_min  0.2954
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(Blessing, 1995)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.074
_exptl_crystal_description       prism
_exptl_crystal_F_000             472
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.455
_refine_diff_density_min         -0.492
_refine_ls_abs_structure_details
;
Flack parameter determined using 518 quotients
[(<i>I</i>^+^)-(<i>I</i>^-^)]/[(<i>I</i>^+^)+(<i>I</i>^-^)]
(Parsons <i>et al.</i>, 2013)
;
_refine_ls_abs_structure_Flack   -0.02(3)
_refine_ls_extinction_coef       0.018(4)
_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   1.042
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     125
_refine_ls_number_reflns         1494
_refine_ls_number_restraints     7
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0513
_refine_ls_R_factor_gt           0.0416
_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^)+(0.0404P)^2^+0.8215P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0929
_refine_ls_wR_factor_ref         0.0977
_reflns_number_gt                1283
_reflns_number_total             1494
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            su2689sup1.cif
_cod_data_source_block           I
_cod_database_code               2239038
_cod_database_fobs_code          2239038
_shelx_hkl_checksum              41568
_shelx_res_checksum              37646
_shelxl_version_number           2.013