4,4-Dimethyl-2,5,8,10-tetraoxatricyclodecane
Hursthouse, Michael B.; Brown, P. M.; Murphy, Patrick J.; Light, Mark E.; Crystal Structure Report Archive  (2002) 32–; doi:

data_1519511
_publ_section_title
;
 4,4-Dimethyl-2,5,8,10-tetraoxatricyclodecane
;
_journal_name_full               'Crystal Structure Report Archive'
_journal_page_first              32
_journal_year                    2002
_chemical_formula_sum            'C8 H12 O4'
_chemical_formula_weight         172.17
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 113.000(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.1183(7)
_cell_length_b                   5.9280(5)
_cell_length_c                   9.0398(7)
_cell_measurement_reflns_used    1741
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.91
_cell_volume                     400.46(6)
_computing_cell_refinement       'DENZO & COLLECT'
_computing_data_collection
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, 1998)'
_computing_data_reduction        'DENZO & COLLECT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker-Nonius KappaCCD'
_diffrn_measurement_method       '\F & \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Bruker-Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0637
_diffrn_reflns_av_sigmaI/netI    0.0734
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3809
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.01
_diffrn_reflns_theta_min         4.22
_exptl_absorpt_coefficient_mu    0.115
_exptl_absorpt_correction_T_max  0.9886
_exptl_absorpt_correction_T_min  0.9774
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SORTAV (Blessing, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.428
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             184
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.178
_refine_diff_density_min         -0.184
_refine_diff_density_rms         0.044
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   2.3(13)
_refine_ls_extinction_coef       0.048(6)
_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   0.995
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     158
_refine_ls_number_reflns         1360
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.995
_refine_ls_R_factor_all          0.0609
_refine_ls_R_factor_gt           0.0374
_refine_ls_shift/su_max          0.011
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0227P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0680
_refine_ls_wR_factor_ref         0.0751
_reflns_number_gt                1063
_reflns_number_total             1360
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            eCrystal-32.cif
_cod_data_source_block           s92
_cod_depositor_comments
;
Citation :
Hursthouse, Michael B. and Brown, P. M. and Murphy, Patrick J. and 
Light, Mark E. (2002) 
University of Southampton, Crystal Structure Report Archive. 
(doi:10.5258/ecrystals/32)

More at:
http://ecrystals.chem.soton.ac.uk/32/

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to the built-in table from CIF Core dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 3271 2015-04-21 07:52:19Z andrius 

2017-03-18
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_sg_symbol_H-M      P21
_cod_original_formula_sum        'C16 H24 O8'
_cod_original_formula_units_Z    1
_cod_original_formula_weight     344.35
_cod_database_code               1519511