2,6-Dibenzoylhydroquinone
Biradha, K.; Desiraju, G. R.; Carrell, H. L.; Katz, A. K.; Acta Crystallographica Section C 52 (1996) 2839–2841; doi:10.1107/S0108270196007615

data_2005675
_publ_section_title
;
 2,6-Dibenzoylhydroquinone
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              2839
_journal_page_last               2841
_journal_paper_doi               10.1107/S0108270196007615
_journal_volume                  52
_journal_year                    1996
_chemical_formula_sum            'C20 H14 O4'
_chemical_formula_weight         318.31
_chemical_melting_point          483
_chemical_name_common            2,6-dibenzoylhydroquinone
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.0310(10)
_cell_length_b                   13.1610(10)
_cell_length_c                   14.4770(10)
_cell_measurement_reflns_used    250
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      18.8
_cell_measurement_theta_min      10.5
_cell_volume                     1530.2(2)
_computing_cell_refinement       MADNES
_computing_data_collection       'MADNES (Enraf-Nonius, 1990)'
_computing_data_reduction        MADNES
_computing_molecular_graphics
'ORTEP (Johnson, 1976), PLUTO (Motherwell & Clegg, 1978)'
_computing_publication_material  SHELXL93
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120
_diffrn_measurement_device
'Enraf-Nonius FAST area detector diffractometer'
_diffrn_measurement_method       rotation
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0350
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2209
_diffrn_reflns_theta_max         28.69
_diffrn_reflns_theta_min         2.81
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.382
_exptl_crystal_density_meas      1.377
_exptl_crystal_density_method    'flotation method'
_exptl_crystal_description       needle
_exptl_crystal_F_000             664
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.682
_refine_diff_density_min         -0.233
_refine_ls_abs_structure_details 'Flack (1983)'
_refine_ls_abs_structure_Flack   -0.3(17)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   0.711
_refine_ls_goodness_of_fit_obs   0.709
_refine_ls_hydrogen_treatment    'H atoms refined isotropically'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     273
_refine_ls_number_reflns         2207
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.730
_refine_ls_restrained_S_obs      0.709
_refine_ls_R_factor_all          0.0575
_refine_ls_R_factor_obs          0.0526
_refine_ls_shift/esd_max         -0.105
_refine_ls_shift/esd_mean        0.011
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.1258P)^2^+2.7021P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1441
_refine_ls_wR_factor_obs         0.1335
_reflns_number_observed          2031
_reflns_number_total             2209
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            pa1231.cif
_cod_data_source_block           dbhq
_cod_depositor_comments
;
The following automatic conversions were performed:

'_diffrn_ambient_temperature' value '120K' was changed to '120' - the
value should be numeric and without a unit designator.

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

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.1258P)^2^+2.7021P] 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^)+(0.1258P)^2^+2.7021P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               2005675