The Khellin Quinone
Yakoubi, Abderrahman; Jalel Eddine Hila; Habib, Boughzala; Bizid, Abdelmalek; Acta Crystallographica Section C 53 (1997) 1949–1950; doi:10.1107/S0108270197010160

data_2006749
_publ_section_title
;
 The Khellin Quinone
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1949
_journal_page_last               1950
_journal_paper_doi               10.1107/S0108270197010160
_journal_volume                  53
_journal_year                    1997
_chemical_formula_moiety         'C12 H6 O5'
_chemical_formula_sum            'C12 H6 O5'
_chemical_formula_weight         230.17
_chemical_name_systematic
;
 2-methyl-5,8-dioxo-5,8-dihydro-furo[3,2-g]chromone
;
_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'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 99.29(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.552(3)
_cell_length_b                   8.1720(10)
_cell_length_c                   15.624(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      15
_cell_measurement_theta_min      13
_cell_volume                     951.6(4)
_computing_cell_refinement       'CAD4 EXPRESS'
_computing_data_collection       'CAD4 EXPRESS (Enraf-Nonius, 1994)'
_computing_data_reduction        'MolEN (Fair, 1990)'
_computing_molecular_graphics    'ORTEPII (Johnson, 1971)'
_computing_publication_material  'SHELXL93 '
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'MULTAN80 (Main et al., 1980)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'CAD4 diffractometer'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0104
_diffrn_reflns_av_sigmaI/netI    0.0254
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2154
_diffrn_reflns_theta_max         26.97
_diffrn_reflns_theta_min         2.64
_diffrn_standards_decay_%        0.4
_diffrn_standards_interval_time  120
_diffrn_standards_number         1
_exptl_absorpt_coefficient_mu    0.128
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.607
_exptl_crystal_density_meas      ?
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             472
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.207
_refine_diff_density_min         -0.174
_refine_ls_extinction_coef       0.0041(13)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.093
_refine_ls_goodness_of_fit_obs   1.190
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     179
_refine_ls_number_reflns         2076
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.093
_refine_ls_restrained_S_obs      1.190
_refine_ls_R_factor_all          0.0799
_refine_ls_R_factor_obs          .0464
_refine_ls_shift/esd_max         -0.001
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0510P)^2^+0.2658P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1205
_refine_ls_wR_factor_obs         .1035
_reflns_number_observed          1353
_reflns_number_total             2076
_reflns_observed_criterion       I>4\s(I)
_cod_data_source_file            ab1487.cif
_cod_data_source_block           khellin
_cod_depositor_comments
;
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 'calc
w=1/[\s^2^(Fo^2^)+(0.0510P)^2^+0.2658P] where P=(Fo^2^+2Fc^2^)/3' 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^(Fo^2^)+(0.0510P)^2^+0.2658P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2006749