22 Space-group changes
Clemente, Dore Augusto; Marzotto, Armando; Acta Crystallographica Section B 59 (2003) 43–50; doi:10.1107/S0108768102022668

data_2103788
_publ_section_title
;
 22 Space-group changes
;
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              43
_journal_page_last               50
_journal_paper_doi               10.1107/S0108768102022668
_journal_volume                  59
_journal_year                    2003
_chemical_formula_moiety         'C22 N2 O6'
_chemical_formula_sum            'C22 N2 O6'
_chemical_formula_weight         388.24
_chemical_name_systematic
;1,1'-Dihydroxy-2,2'-(1,4,7,10-tetraoxadeca-1,10-diyl)-6,6'-(2,5-diazahexa-1,5-
-diene-1,6-diyl)dibenzene
;
_space_group_IT_number           19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.148(2)
_cell_length_b                   8.251(2)
_cell_length_c                   21.690(2)
_cell_measurement_temperature    293(2)
_cell_volume                     2174.1(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.382
_diffrn_measured_fraction_theta_max 0.382
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0212
_diffrn_reflns_av_sigmaI/netI    0.0872
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            12290
_diffrn_reflns_theta_full        32.87
_diffrn_reflns_theta_max         32.87
_diffrn_reflns_theta_min         1.88
_exptl_absorpt_coefficient_mu    0.090
_exptl_crystal_density_diffrn    1.186
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             776
_refine_diff_density_max         0.588
_refine_diff_density_min         -0.577
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.1(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.631
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     121
_refine_ls_number_reflns         3081
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.631
_refine_ls_R_factor_all          0.0195
_refine_ls_R_factor_gt           0.0193
_refine_ls_shift/su_max          0.745
_refine_ls_shift/su_mean         0.006
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0178P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0699
_refine_ls_wR_factor_ref         0.0767
_reflns_number_gt                3050
_reflns_number_total             3081
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            an0613.cif
_cod_data_source_block           nohned
_cod_database_code               2103788