(<i>Z</i>,2<i>R</i>,3<i>R</i>,4a<i>R</i>,7<i>R</i>,12a<i>S</i>)-2,3,7,8,12,12a-Hexahydro-2,3-dimethoxy-2,3,7-trimethyl-4a<i>H</i>-[1,4]dioxino[2,3-<i>c</i>]oxecin-5(11<i>H</i>)-one: a commensurate occupationally modulated structure revealing a condition for diffraction symmetry enhancement for non-parent reflections
A. David Rae; Anthony C. Willis; David T. Loong; Martin G. Banwell; Acta Crystallographica Section B 62 (2006) 262–267; doi:10.1107/S0108768105041650

data_2100425
_publ_contact_author_address
;
Research School of Chemistry,
Australian National University,
Canberra, A. C. T. 0200, Australia
;
_publ_contact_author_email       ' rae@rsc.anu.edu.au '
_publ_contact_author_fax         ' 61 2 6125 0750 '
_publ_contact_author_name        ' A. David Rae'
_publ_contact_author_phone       ' 61 2 6125 3895 '
_publ_section_title
;(<i>Z</i>,2<i>R</i>,3<i>R</i>,4a<i>R</i>,7<i>R</i>,12a<i>S</i>)-2,3,7,8,12,12a-Hexahydro-2,3-dimethoxy-2,3,7-trimethyl-4a<i>H</i>-[1,4]dioxino[2,3-<i>c</i>]oxecin-5(11<i>H</i>)-one:
 a commensurate occupationally modulated structure revealing a condition for
 diffraction symmetry enhancement for non-parent reflections
;
_journal_coeditor_code           CK5012
_journal_date_accepted           2005-12-13
_journal_date_recd_electronic    2005-04-04
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              262
_journal_page_last               267
_journal_paper_category          FA
_journal_paper_doi               10.1107/S0108768105041650
_journal_volume                  62
_journal_year                    2006
_chemical_formula_moiety         'C16 H26 O6 '
_chemical_formula_sum            'C16 H26 O6'
_chemical_formula_weight         314.378
_space_group_IT_number           144
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 31'
_symmetry_space_group_name_H-M   'P 31'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           maXus
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            9
_cell_length_a                   18.6850(2)
_cell_length_b                   18.6850(2)
_cell_length_c                   12.25390(10)
_cell_measurement_reflns_used    84318
_cell_measurement_temperature    200
_cell_measurement_theta_max      27.485
_cell_measurement_theta_min      2.546
_cell_volume                     3705.03(6)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection
;
 COLLECT (Nonius BV, 1997)
;
_computing_data_reduction        'Denzo and Scalepak (Otwinowski & Minor, 1997)'
_computing_molecular_graphics
;
ORTEP-II (Johnson 1976) in teXsan (MSC, 1992-1997)
;
_computing_publication_material  'maXus(Mackay et al., 1999)'
_computing_structure_refinement  'RAELS2000 (Rae 2000)'
_computing_structure_solution
'SIR97(Cascarano al.,Acta Cryst.,1996,A52,C-79)'
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type
;
Enraf Nonius Kappa CCD
;
_diffrn_measurement_method       ' \f and \w scans with CCD '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           ' MoK\a'
_diffrn_reflns_av_R_equivalents  0.055
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            98252
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         2.74
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_T_max  0.985
_exptl_absorpt_correction_T_min  0.963
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details
;
via Gaussian method (Coppens, 1970) implemented in maXus (2000)
;
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.268
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1530
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.28
_refine_diff_density_max         .255
_refine_diff_density_min         -.230
_refine_ls_abs_structure_details
;
The enantiomer has been assigned by reference to an unchanging chiral
centre in the synthetic procedure.
;
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.281
_refine_ls_goodness_of_fit_ref   1.292
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     707
_refine_ls_number_reflns         5022
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.043
_refine_ls_R_factor_gt           0.038
_refine_ls_shift/su_max          .1
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
w = 1 / ( \s^2^(Fo^2^) + 0.0009 \\times Fo^2^)
;
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_all         0.050
_refine_ls_wR_factor_gt          0.048
_refine_ls_wR_factor_ref         0.048
_reflns_number_gt                5022
_reflns_number_total             5629
_reflns_threshold_expression     'I> 3.00 \s(I)'
_cod_data_source_file            ck5012.cif
_cod_data_source_block           mgb045_rae
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Trigonal' changed to 'trigonal' 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:

'_symmetry_cell_setting' value 'Trigonal' changed to 'trigonal'
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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_cell_volume        3705.02(6)
_cod_original_sg_symbol_H-M      'P 31          '
_cod_original_formula_sum        'C16 H26 O6 '
_cod_database_code               2100425